CRISIS came to Middle English as a medical word: "the decisive point in the progress of a disease," in other words, that change in a patient's condition which indicates recovery or death. But also it had or quickly acquired a general sense of "vitally important or decisive state of things, point at which change must come for better or worse."
And here we stand, facing the word in both its original senses.
As with much of the early medical terminology, CRISIS migrated to English from Greece via Rome. The Greek word is krisis, and it was used in medicine by Hippocrates and Galen, but its general sense in ancient Greek was "judgment, the result of a trial, a selection." It is from the verb krinein "to separate, decide, judge," which probably is from a PIE root meaning "to sieve."
To sieve or sift is, figuratively "to discriminate, to distinguish" (as when the police inspectors "sift through the evidence"). Sifting and winnowing were essential activities in agricultural communities, and their purpose is to separate that which is good or usable from that which is neither. Judgment is implied.
The Old English cognate is hriddel "a sieve." Native English had the word only in a literal sense, and its best-known survival now probably is the derived verb RIDDLE "perforate with many holes." (The other RIDDLE, the "word-puzzle" sense, is from a different root and is related to READ and RHYME).
But beyond homely Old English the PIE "sieve" root has had a prolific sense development. In Latin it yielded both literal (cribrum "a sieve") and figurative senses (crimen "indictment, accusation"), and words that had both: cernere "to sift, separate," also "to distinguish."
So, among other words, Latin gave English CERTAIN "determined, fixed," from certus "determined, resolved, fixed settled," used of things whose qualities are invariable, also "established," also "placed beyond doubt, sure, true, proved, to be depended upon," all from the image of that which has been sifted.
And from the Greek branch of the family comes CRITIC "one who passes judgment, person skilled in judging merit in some particular class of things," from Greek kritikos "able to make judgments," from krinein.
Other Modern English words in the family include ASCERTAIN; CONCERN (which has changed meaning since Latin formed it); CONCERT (which underwent an even more inexplicable sense shift); CRIME; DECREE (the pronouncing of a decision); DISCERN; DISCRIMINATE; EXCREMENT (that which is "sifted out" or discharged from the body); HYPOCRISY (the sense evolution in Attic Greek is from "separate gradually" to "to answer" to "answer a fellow actor on stage" to "play a part"), and INCERTITUDE.
EPIDEMIC is a case of a noun with an adjective's ending. But that's because, in common with the noun senses of COMIC, SCHEMATIC, etc. it is short for a noun phrase -- epidemic disease or something like it. The noun use dates to the mid-18th century. The adjective is from c. 1600 in English.
Its meaning is "common to or affecting a whole people." It was originally and still is, used in reference to diseases. It's from Greek epidemia "a stay in a place;" also "prevalence of an epidemic disease" (especially the plague), from epi "among, upon" + dēmos "people, district." That's the same word that's in DEMOCRACY and DEMOGRAPHICS.
The earlier noun form in English was EPIDEMY. An Old English noun for a disease that appears to be everywhere at once was man-cwealm. That second word meant "death, murder, slaughter; disaster; plague; torment," and probably was related to cwellan "to kill, murder, execute," which survives in a much-softened sense in QUELL.
A PANDEMIC is different, but the exact distinction is fuzzy and not always observed. The Greek word behind it is pandemos "pertaining to all people; public, common," from pan- "all." It's a more modern word in English, modeled on EPIDEMIC.
VIRUS is, unsurprisingly, one of the most-searched-for words these days. Viruses themselves weren't discovered until the 1880s, but the word taken to describe them is much older in English. VIRUS itself is identical to the Latin word it comes from, and its older sense, in English and Latin, was "poisonous substance," especially a liquid. The reconstructed PIE root of it was a word that seems to have been used of foul or malodorous fluids, but with specialization in some languages to "poisonous fluid."
VIRUS had an intermediate step between "poison" and "microscopic infectious agent that replicates inside the living cells of an organism." It was used in the 18th and early 19th centuries for "any agent that causes infectious disease."
From figurative senses of VIRUS in the old "poison" meaning we get words like VIRULENT and VIRULENCE. These were used earlier in medicine, in reference to wounds or ulcers that were "full of corrupt or poisonous matter." The figurative senses seem to date from c. 1600.
VIRAL is a 20th century word, originally "of the nature of, or caused by, a virus." The internet sense of "become suddenly widely popular through sharing" seems to be from the 1990s, originally in the jargon of marketing, and is based on the spread of a computer virus.
CORONA is the Latin word for "a crown, a garland," in ancient Rome especially "a crown or garland bestowed for distinguished military service." Our English CROWN is just the same Latin word passed through French, which beat a few sounds out of it.
Since it left Latin it has acquired many extended senses in botany, anatomy, cigars, beers, etc. A CORONAVIRUS is so called for the spikes that protrude from its membranes and resemble the tines of a crown or the corona of the sun. When I wrote that entry probably very few people had seen a representation of one. Now, probably, all of you have.
The word QUARANTINE carries echoes of earlier plagues. The QUAR- element in a word often denotes "four" in some way. A quarantine was the name for the period a ship suspected of carrying disease was kept in isolation.
The idea, and the word in this sense, comes from Italian -- quaranta giorni, literally "space of forty days." The major Italian commercial cities, especially Venice, carried on a heavy trade with the eastern Mediterranean, where plague outbreaks were common, so the policy developed of keeping even clean ships from those regions waiting outside the port long enough for latent cases to show. The policy dates to the great bubonic plague epidemics of the 14th century.
The forty days probably was not based on any scientific medical observation. It would have been a more-than-sufficiently long period for the purpose, but 40 was used frequently to indicate any large, round number, and especially in reference to time periods. For that, you have to go to the Bible.
Your objective through this experience: A SANE mind in a SANITIZED body. They're the same word. SANE "of sound mind, mentally sound" is early 18th century (SANITY "soundness of mind" is from c. 1600).
But before that, SANE and SANITY referred to bodily health, as their relatives SANITARY and SANITIZE still do. Latin sanus, the adjective responsible for all of them, meant primarily "sound, healthy," but it also had a figurative or transferred use, "of sound mind, rational, sane."
Its origin is uncertain. According to de Vaan, formally it looks like it could be from a PIE root meaning "to tie." If so, the sense could be "which is in place, in order." But he says it might also be from a different root meaning "to satisfy" (as in SATIS "enough").
INOCULATION describes the older form of the process that was used to protect against smallpox. Another word for it in 18th century English was VARIOLATION, from VARIOLA, the medical Latin word for "smallpox," which is a diminutive of Latin varius "changing, various," in this case "speckled, spotted" (related to VARY and VARIOUS).
Inoculation against smallpox was discovered independently or passed from place to place, and was practiced in Asia and Africa before it was brought to Europe. It became possible after people realized there were two forms of smallpox: a minor one that killed 2% or less of the people who got it, and a major form that had about a 30% mortality and typically left survivors with severe scarring and often blinded them.
The key observation was that, whether you got the major or the minor form, if you survived, you were immune thereafter to both forms. So doctors would deliberately infect healthy young patients with a local dose of the minor smallpox, usually resulting in a mild case of it at worst, to render them immune to the more deadly form. The English seem to have picked up the custom in Constantinople in the early 1700s.
The story of the discovery of vaccination is better-known. There was a disease similar to smallpox that affected cows, and milkmaids sometimes contracted it from touching the udders. Thus it was called COWPOX and it was much milder in humans than smallpox. And anyone once infected with cowpox never then contracted smallpox. Scientists in Europe were experimenting with this in the late 1700s. English polymath Edward Jenner got the results of his experiment into publication, and they were widely read and influential, so he gets credit for the discovery. But a community of minds was involved.
It also seems unfair to overlook little James Phipps, the 8-year-old son of Jenner's gardener, who was injected with the pus from a cowpox lesion, then, starting two months later, was injected with the deadly dangerous smallpox more than twenty times to prove Jenner's cowpox vaccination had worked. (He lived until 1853; when Phipps had grown and married, Jenner gave him free lease on a cottage.)
Jenner, as the public face of the new treatment, also got to name it. He chose VACCINE, from Latin vaccinus, which means "from cows," from vacca, the Latin word for "cow."
The medical use of INOCULATION is a word and an image from agriculture; it's based on the old use of "eye" words for the buds of plants, perhaps because of their "opening." Latin inoculare meant "implant a bud of one plant into a cut in another," which still is how you graft. When Europeans learned the variolation technique, one of the methods was to make a small slit in the skin of the hand and rub on it a scab from a patient with minor smallpox. This was similar enough to suggest a grafting.
The Latin word is from in- "in" + oculus "a bud," but originally and usually "eye," from PIE root *okw- "to see," which also produced Greek opsis (which gave English OPTICS and all the -OPSY words) and, apparently also, native EYE and the Germanic words, though the evolution of these from the root is irregular.
As vaccination was much safer than variolation (it didn't involve smallpox at all), it drove out the older method of protection, and VACCINATION and INOCULATION ran together into one meaning.
Of course, you can avoid both and use IMMUNIZATION.
HOSPITAL is the same word as HOTEL (and HOSTEL, and, partly, HOSPICE), and is related to both GUEST and HOST, and to HOSPITALITY and HOSTILITY. It's one of the word-groups that takes you into the deepest trenches of language history and gives you a whiff of the ancestral homelands.
HOSPITAL - mid-13c., "shelter for the needy," from Old French hospital, ospital "hostel, shelter, lodging" (Modern French hôpital), from Late Latin hospitale "guest-house, inn," noun use of neuter of Latin adjective hospitalis "of a guest or host" (as a noun, "a guest; the duties of hospitality"), from hospes (genitive hospitis) "guest; host."
The meaning "institution for sick or wounded people" in English is recorded by the 1540s. The sense shift in Latin from duties to buildings might have been via the common term cubiculum hospitalis "guest-chamber."
HOTEL in English is a later borrowing (17th century) from the French form of the Latin word -- hôtel, from Old French hostel. Its oldest sense was a mansion or large house; the meaning "an inn of the better sort" is by 1765. HOSTEL is in between, a Middle English borrowing of the Old French form of the word. It went obsolete after the 16th century but was revived in the 19th by Sir Walter Scott and later reinforced by the rise of youth hostels.
The presumed/reconstructed Proto-Indo-European root of the Latin word would look something like *ghos-ti- if you wrote it in the modern English alphabet.
It meant "stranger, guest, host," properly "someone with whom one has reciprocal duties of hospitality," representing "a mutual exchange relationship highly important to ancient Indo-European society" [Watkins]. As strangers are potential enemies as well as guests, the word has a forked path. Watkins went on to describe this:
The word ghos-ti- was thus the central expression of the guest-host relationship, a mutual exchange relationship highly important to ancient Indo-European society. A guest-friendship was a bond of trust between two people that was accompanied by ritualized gift-giving and created an obligation of mutual hospitality and friendship that, once established, could continue in perpetuity and be renewed years later by the same parties or their descendants. [Calvert Watkins, "American Heritage Dictionary of Indo-European Roots"]
And as the academic lulling sentence ends you stand on rough grass that runs flat to the horizon, with lowing herds on the move, driven by pelt-clad horsemen, their families crammed in heavy wheeled carts, odor of smoke and dung, the dirty, serious faces of the children whose scions will create the Parthenon and "Hamlet" and crack the atom and the DNA.
It is the hypothetical source of/evidence for its existence is provided by: Greek xenos "guest, host, stranger;" Latin hostis, in earlier use "a stranger," in classical use "an enemy," hospes "host;" Old Church Slavonic gosti "guest, friend," gospodi "lord, master;" Old English gæst, "chance comer, a stranger."
DRACONIAN: "of or pertaining to Draco," the ancient Greek statesman. Usually in reference to laws, "rigorous, extremely severe or harsh." Draco is the Latinized form of Greek Drakon, the name of the archon of Athens who laid down a code of laws for Athens c. 621 B.C.E. that mandated death as punishment for minor crimes. (They were at least consistent; the earlier law code was oral and often arbitrarily interpreted.) No full version of the laws seems to have survived.
His name seems to mean literally "sharp-sighted" and to come from drak-, the strong aorist stem of Greek derkesthai "to see clearly." Drakon is the same word that the Greeks used for a mythical serpent or giant sea-creature. There the sense is, perhaps, "the one with the (deadly) glance." More than a few fabulous beasts could kill with a glance.
The Greek word in that latter sense passed to Latin as draco (accusative draconem) and, via the accusative and Old French, to Middle English as DRAGON. A version of the same Latin word, from the nominative case, came to English as DRAKE.
A kind of early firearm also was called a "dragon" in French, probably because it "breathed fire," and the name was transferred from the weapon to the soldiers that used it, who came to be called, in the English spelling of the French pronunciation, DRAGOONS.
As the French king used his dragoons to persecute Protestants in the 17th century religious wars, DRAGOON came to be a verb meaning "to compel by threats or harassment."
Which is what they're likely to do to you under Draconian measures.
HORDES of HOARDERS
HOARD "an accumulation of something for preservation or future use" goes right back to Old English and on into Proto-Germanic. It has relatives in most of the Germanic languages, living and dead.
The reconstructed Proto-Indo-European root is a verb meaning "to cover, conceal." Among its supposed relatives, via that origin, are CUSTODY (from the notion of "guard, keep, protect"); HIDE "to conceal;" possibly HUT; and OBSCURE (Latin ob "over" + -scurus "covered").
HORDE isn't even Indo-European. It appears in English in the 16th century meaning "tribe of Asiatic nomads living in tents," and it's from a West Turkic language (compare Tatar urda "horde," Turkish ordu "camp, army"), borrowed into English via Polish, French, or Spanish. URDU, the official language of Pakistan, is from the Turkish word; it is short for zaban-i-urdu "language of the camp." "So named because it grew up since the eleventh century in the camps of the Mohammedan conquerors of India as a means of communication between them and the subject population of central Hindustan" [Century Dictionary].
The OED says the initial h- in the English word seems to have been acquired in Polish. The transferred sense of "uncivilized gang" is from the 1610s.