1620s, vorloffe, "leave of absence," especially in military use, "leave or license given by a commanding officer to an officer or a soldier to be absent from service for a certain time," from Dutch verlof, literally "permission," from Middle Dutch ver- "completely, for" + laf, lof "permission," from Proto-Germanic *laubo-, from PIE root *leubh- "to care, desire, love." In English, the elements of it are for- + leave. The -gh spelling predominated from 1770s and represents the "f" that had been pronounced at the end of the word but later disappeared in English.

The spelling furloe occurs in the 18th century, but furlough appears to be the earliest spelling (as in Blount's Gloss., ed. 1674). As the spelling furlough does not follow that of the orig. language, it was prob. intended to be phonetic (from a military point of view), the gh perhaps as f and the accent on the second syllable .... [Century Dictionary]

By 1946 in reference to temporary layoffs of workers (originally of civilian employees in the U.S. military); by 1975 applied to conditional temporary releases of prisoners for the purpose of going to jobs (work-release).

c. 1200, "in life, living," contraction of Old English on life "in living, not dead," from a- (1) + dative of lif "life" (see life). The full form on live was still current 17c. Of abstract things (love, lawsuits, etc.) "in a state of operation, unextinguished," c. 1600. From 1709 as "active, lively;" 1732 as "attentive, open" (usually with to). Used emphatically, especially with man (n.); as in:

[A]bout a thousand gentlemen having bought his almanacks for this year, merely to find what he said against me, at every line they read they would lift up their eyes, and cry out betwixt rage and laughter, "they were sure no man alive ever writ such damned stuff as this." [Jonathan Swift, "Bickerstaff's Vindication," 1709]

Thus it was abstracted as an expletive, man alive! (1845). Alive and kicking "alert, vigorous," attested from 1823; Farmer says "The allusion is to a child in the womb after quickening," but kicking in the sense "lively and active" is recorded from 1550s (e.g. "the wanton or kicking flesh of yong maydes," "Lives of Women Saints," c. 1610).

c. 1200, purgatorie, "place or condition of temporal punishment for spiritual cleansing after death of souls dying penitent and destined ultimately for Heaven," from Old French purgatore, purgatoire and directly from Medieval Latin purgatorium (St. Bernard, early 12c.), in Latin, "means of cleansing," noun use of neuter of purgatorius (adj.) "purging, cleansing," from purgat-, past-participle stem of Latin purgare "to cleanse, purify" (see purge (v.)).

It is not considered as a place of probation ; for the ultimate salvation of those in purgatory is assured, and the impenitent are not received into purgatory. The souls in purgatory are supposed, however, to receive relief through the prayers of the faithful and through the sacrifice of the mass. The common belief in the Latin Church is that the purgatorial suffering is by fire ; the Greek Church, however, does not determine its nature. [Century Dictionary]

The figurative use for "state of mental or emotional suffering, expiation, etc." is from late 14c., originally especially when due to unrequited love, or, (seemingly paradoxically), marriage (e.g. Lydgate's wyfly purgatorye). In old New England it was used of narrow gorges and steep-sided ravines. Related: Purgatorial; purgatorian. 

"a very hard stone," mid-14c., adamant, adamaunt, from Old French adamant "diamond; magnet" or directly from Latin adamantem (nominative adamas) "adamant, hardest iron, steel," also used figuratively, of character, from Greek adamas (genitive adamantos), the name of a hypothetical hardest material.

It is a noun use of an adjective meaning "unbreakable, inflexible," which was metaphoric of anything unalterable (such as Hades) and is of uncertain origin. It is perhaps literally "invincible, indomitable," from a- "not" (see a- (3)) + daman "to conquer, to tame," from PIE root *deme- "to constrain, force, break (horses)," for which see tame (adj.). "But semantically, the etymology is rather strange," according to Beekes, who suggests it might be a foreign word altered in Greek by folk etymology, and compares Akkadian (Semitic) adamu.

Applied in antiquity to a metal resembling gold (Plato), white sapphire (Pliny), magnet (Ovid, perhaps through confusion with Latin adamare "to love passionately"), steel, emery stone, and especially diamond, which is a variant of this word. "The name has thus always been of indefinite and fluctuating sense" [Century Dictionary]. The word had been in Old English as aðamans, but the modern word is a re-borrowing.

Old English heorte "heart (hollow muscular organ that circulates blood); breast, soul, spirit, will, desire; courage; mind, intellect," from Proto-Germanic *hertan- (source also of Old Saxon herta, Old Frisian herte, Old Norse hjarta, Dutch hart, Old High German herza, German Herz, Gothic hairto), from PIE root *kerd- "heart."

Spelling with -ea- is c. 1500, reflecting what then was a long vowel, and the spelling remained when the pronunciation shifted. Most of the modern figurative senses were present in Old English, including "memory" (from the notion of the heart as the seat of all mental faculties, now only in by heart, which is from late 14c.), "seat of inmost feelings; will; seat of emotions, especially love and affection; seat of courage." Meaning "inner part of anything" is from early 14c. In reference to the conventional heart-shape in illustration, late 15c.; heart-shaped is from 1744.

Heart attack attested from 1875; heart disease is from 1864. The card game hearts is so called from 1886. To have one's heart in the right place "mean well" is from 1774. Heart and soul "one's whole being" is from 1650s. To eat (one's own) heart "waste away with grief, resentment, etc." is from 1580s.

1610s, "native or inhabitant of Malta;" 1797 (adj.) "of or pertaining to Malta, from Malta + -ese. Maltese cross is from 1754 (earlier Malta cross, 1650s), so called because it was worn by the Knights of Malta. Maltese cat is attested from 1830: any cat with fur completely or primarily gray or blue, supposedly a common trait among cats on the island, but the breeds that noted for this coloring are not associated with Malta. As a type of very small dog, known since ancient times in the Mediterranean, it is attested in English by 1803.

Strabo informs us, that "there is a town in Pachynus, a promontory of Sicily, (called Meleta,) from whence are transported many fine little dogs, called Melitae Canes. They were accounted the jewels of women; but now the said town is possessed by fishermen, and there is no such reckoning made of those tender little dogs, which are not bigger than common ferrets or weasels; yet are they not small in understanding, nor unstable in their love to men, for which cause they are also nourished tenderly for pleasure." [Capt. Thomas Brown, "Biographical Sketches and Authentic Anecdotes of Dogs," Edinburgh, 1829]

"impressed with fear, fearful," early 14c., originally the past participle of the now-obsolete Middle English verb afray "frighten," from Anglo-French afrayer, Old French affrai, effrei, esfrei "disturbance, fright," from esfreer (v.) "to worry, concern, trouble, disturb," from Vulgar Latin *exfridare, a hybrid word meaning literally "to take out of peace."

The first element is from Latin ex "out of" (see ex-). The second is Frankish *frithu "peace," from Proto-Germanic *frithuz "peace, consideration, forbearance" (source also of Old Saxon frithu, Old English friu, Old High German fridu "peace, truce," German Freide "peace"), from a suffixed form of PIE root *pri- "to be friendly, to love."

A rare case of an English adjective that never stands before a noun. Because it was used in the King James Bible, it acquired independent standing and thrived while affray faded, and it chased off the once more common afeared. Colloquial sense in I'm afraid "I regret to say, I suspect" (without implication of fear, as a polite introduction to a correction, admission, etc.) is recorded by 1590s.

Her blue affrayed eyes wide open shone [Keats, "The Eve of St. Agnes," 1820]

kind of thick, soft leather, 1570s, buffe leather "leather made of buffalo hide," from  French buffle "buffalo" (15c., via Italian, from Latin bufalus; see buffalo (n.)).

The color term "light brownish-yellow" (by 1788) comes via the hue of buff leather. The old association of "hide" and "skin" led c. 1600 to the sense in in the buff "naked." Buff-colored uniforms of New York City volunteer firefighters since 1820s led to the meaning "enthusiast" (1903).

These men, together with a score or more of young boys who cherish ambitions to be firemen some day, make up the unofficial Fire Department of New York, and any one who imagines they are not a valuable branch of the service need only ask any firemen [sic] what he thinks of the Buffs to find out his mistake. The Buffs are men and boys whose love of fires, fire-fighting and firemen is a predominant characteristic, who simply cannot keep away from fires, no matter at what time of the day or night they occur, or how long they continue. [New York Sun, Feb. 4, 1903]

Middle English snake, "a long, limbless reptile," from Old English snaca, from Proto-Germanic *snakon (source also of Old Norse snakr "snake," Swedish snok, German Schnake "ring snake"), from PIE root *sneg- "to crawl, creeping thing" (source also of Old Irish snaighim "to creep," Lithuanian snakė "snail," Old High German snahhan "to creep"). In Modern English, gradually replacing serpent in popular use.

Traditionally applied to the British serpent, as distinguished from the venomous adder. Applied from 17c. to various snake-like devices and appliances. Snakes! as an exclamation is from 1839.

The meaning "treacherous person" is attested by 1580s (it was used of Satan in early 15c., and serpent and adder are older in this sense) Compare Old Church Slavonic gadu "reptile," gadinu "foul, hateful." The snake's reputation was not helped by the Genesis story, but the notion is older. The phrase snake in the grass "underhand, plotting, deceitful person" translates Virgil's Latet anguis in herba [Ecl. III:93].

Snake eyes in crap-shooting, "a throw of two ones" (the lowest possible roll), is from 1919, hence the association with bad luck. This might have influenced snake-bitten, snake-bit "unlucky," attested in sports slang by 1957, which also might be from a literal sense (attested by 1807), perhaps suggesting one doomed by a venomous bite.

The board game of Snakes and Ladders is attested from 1907. Snake charmer is from 1813. Snake pit is from 1883, as a supposed primitive test of truth or courage; the figurative sense is from 1941. Snake dance is by 1772 in reference to a Hopi ceremony; by 1911 as a party dance.