late 14c., in logic, "a class of individuals or things," from Latin species "a particular sort, kind, or type" (opposed to genus), originally "a sight, look, view; outward appearance, shape, form," a derivative of specere "to look at, to see, behold" (from PIE root *spek- "to observe"). In English it is attested from 1550s as "appearance, outward form."
Latin species "a sight; outward appearance" had many extended senses, including "a spectacle; a mental appearance, an idea or notion;" also "semblance, pretext; manner, fashion; display, beauty; a likeness or statue; reputation, honor." Typically it was used in passive senses. Also compare spice (n.).
In Late Latin, in logic and legal language, it acquired the meaning "a special case," especially (as a translation of Greek eidos) "a class included under a higher class; a kind; a sort; a number of individuals having common characteristics peculiar to them." The notion (as Lewis & Short puts it) is "The particular thing among many to which the looks are turned."
The English word is attested from 1560s as "a distinct class (of something) based on common characteristics." The specific use in biological sciences in reference to groups of living things recognizably distinct from all others by their inherited characteristics is from c. 1600. Endangered species is attested by 1964.
Old English þis, neuter demonstrative pronoun and adjective (masc. þes, fem. þeos), probably from a North Sea Germanic pronoun *tha-si-, formed by combining the base *þa- (see that) with -s, which is probably identical with Old English se "the" (representing here "a specific thing"), or with Old English seo, imperative of see (v.) "to behold." Compare Old Saxon these, Old Frisian this, Old Norse þessi, Middle Dutch dese, Dutch deze, Old High German deser, German dieser.
Once fully inflected, with 10 distinct forms; the oblique cases and other genders gradually fell away by 15c. The Old English plural was þæs (nominative and accusative), which in Northern Middle English became thas, and in Midlands and Southern England became thos. The Southern form began to be used late 13c. as the plural of that (replacing Middle English tho, from Old English þa) and acquired an -e (apparently from the influence of Middle English adjective plurals in -e; compare alle from all, summe from sum "some"), emerging early 14c. as modern those.
About 1175 thes (probably a variant of Old English þæs) began to be used as the plural of this, and by 1200 it had taken the form these, the final -e acquired via the same mechanism that gave one to those.
Old English locian "use the eyes for seeing, gaze, look, behold, spy," from West Germanic *lokjan (source also of Old Saxon lokon "see, look, spy," Middle Dutch loeken "to look," Old High German luogen, German dialectal lugen "to look out"), a word of unknown origin. Breton lagud "eye" has been suggested as a possible cognate.
In Old English, usually with on; the use of at began 14c. As a word to call attention, c. 1200 (look out! "take notice" is from mid-15c.). Meaning "seek, search out" is c. 1300; meaning "to have a certain appearance, express or manifest by looks" is from c. 1400. Of objects, "to face in a certain direction," late 14c. To look like "have the appearance of" is from mid-15c. Look after "take care of" is from late 14c., earlier "to seek" (c. 1300), "to look toward" (c. 1200). Look into "investigate" is from 1580s. To look forward "anticipate" is c. 1600; especially "anticipate with pleasure" from mid-19c. To look over "scrutinize" is from mid-15c.
Look up is from c. 1200 in literal sense "raise the eyes;" as "research in books or papers" from 1690s. To look up to "regard with respect and veneration" is from 1719. To look down upon in the figurative sense "regard as beneath one" is from 1711; to look down one's nose is from 1921. To not look back "make no pauses" is colloquial, first attested 1893. In look sharp (1711), sharp originally was an adverb, "sharply." To look around "search about, look round" is from 1883.
Old English fæder "he who begets a child, nearest male ancestor;" also "any lineal male ancestor; the Supreme Being," and by late Old English, "one who exercises parental care over another," from Proto-Germanic *fader (source also of Old Saxon fadar, Old Frisian feder, Dutch vader, Old Norse faðir, Old High German fatar, German vater; in Gothic usually expressed by atta), from PIE *pəter- "father" (source also of Sanskrit pitar-, Greek pater, Latin pater, Old Persian pita, Old Irish athir "father"), presumably from baby-speak sound "pa." The ending formerly was regarded as an agent-noun affix.
My heart leaps up when I behold
A rainbow in the sky:
So was it when my life began;
So is it now I am a man;
So be it when I shall grow old,
Or let me die!
The Child is father of the Man;
I could wish my days to be
Bound each to each by natural piety.
The classic example of Grimm's Law, where PIE "p-" becomes Germanic "f-." Spelling with -th- (15c.) reflects widespread phonetic shift in Middle English that turned -der to -ther in many words, perhaps reinforced in this case by Old Norse forms; spelling caught up to pronunciation in 1500s (compare mother (n.), weather (n.), hither, gather). As a title of various Church dignitaries from c. 1300; meaning "creator, inventor, author" is from mid-14c.; that of "anything that gives rise to something else" is from late 14c. As a respectful title for an older man, recorded from 1550s. Father-figure is from 1954. Fathers "leading men, elders" is from 1580s.
mid-13c., mirour, "polished surface (of metal, coated glass, etc.) used to reflect images of objects," especially the face of a person, from Old French mireoir "a reflecting glass, looking glass; observation, model, example," earlier miradoir (11c.), from mirer "look at" (oneself in a mirror), "observe, watch, contemplate," from Vulgar Latin *mirare "to look at," variant of Latin mirari "to wonder at, admire" (see miracle).
The Spanish cognate, mirador (from mirar "to look, look at, behold"), has come to mean "watch tower, gallery commanding an extensive view." Latin speculum "mirror" (or its Medieval Latin variant speglum) is the source of words for "mirror" in neighboring languages: Italian specchio, Spanish espejo, Old High German spiegal, German Spiegel, Dutch spiegel, Danish spejl, Swedish spegel. An ancient Germanic group of words for "mirror" is represented by Gothic skuggwa, Old Norse skuggsja, Old High German scucar, which are related to Old English scua "shade, shadow."
Words for 'mirror' are mostly from verbs for 'look', with a few words for 'shadow' or other sources. The common use of the word for the material 'glass' in the sense of 'mirror' seems to be peculiar to English. [Carl Darling Buck, "A Dictionary of Selected Synonyms in the Principal Indo-European Languages," 1949]
Figurative use, "that in or by which anything is shown or exemplified," hence "a model (of good or virtuous conduct)" is attested from c. 1300. Mirrors have been used in divination since classical and biblical times, and according to folklorists, in modern England they are the subject of at least 14 known superstitions. Belief that breaking one brings bad luck is attested from 1777. Mirror image "something identical to another but having right and left reversed" is by 1864. Mirror ball attested from 1968. To look in (the) mirror in the figurative sense of "examine oneself" is by early 15c.