buckeye (n.)

"male deer," c. 1300, earlier "male goat;" from Old English bucca "male goat," from Proto-Germanic *bukkon (source also of Old Saxon buck, Middle Dutch boc, Dutch bok, Old High German boc, German Bock, Old Norse bokkr), perhaps from a PIE root *bhugo (source also of Avestan buza "buck, goat," Armenian buc "lamb"), but some speculate that it is from a lost pre-Germanic language. Barnhart says Old English buc "male deer," listed in some sources, is a "ghost word or scribal error." The Germanic word (in the sense "he-goat") was borrowed in French as bouc.

The meaning "a man" is from c. 1300 (Old Norse bokki also was used in this sense). Especially "fashionable man" (1725); also used of a male Native American (c. 1800) or Negro (1835). This also is perhaps the sense in army slang buck private "private of the lowest class" (1870s).

The phrase pass the buck is recorded in the literal sense 1865, American English poker slang; the buck in question being originally perhaps a buckhorn-handled knife:

The 'buck' is any inanimate object, usually [a] knife or pencil, which is thrown into a jack pot and temporarily taken by the winner of the pot. Whenever the deal reaches the holder of the 'buck', a new jack pot must be made. [J.W. Keller, "Draw Poker," 1887]

The figurative sense of "shift responsibility" is first recorded 1912; the phrase the buck stops here (1952) is associated with U.S. President Harry Truman.

c. 1200, from Old English ege (Mercian), eage (West Saxon) "eye; region around the eye; apperture, hole," from Proto-Germanic *augon (source also of Old Saxon aga, Old Frisian age, Old Norse auga, Swedish öga, Danish øie, Middle Dutch oghe, Dutch oog, Old High German ouga, German Auge, Gothic augo "eye"). Apparently the Germanic form evolved irregularly from PIE root *okw- "to see."

HAMLET: My father — methinks I see my father.

HORATIO: Where, my lord?

HAMLET: In my mind's eye, Horatio.

Until late 14c. the English plural was in -an, hence modern dialectal plural een, ene. Of potatoes from 1670s. Of peacock feathers from late 14c. As a loop used with a hook in fastening (clothes, etc.) from 1590s. The eye of a needle was in Old English. As "the center of revolution" of anything from 1760. Nautical in the wind's eye "in the direction of the wind" is from 1560s.

To see eye to eye is from Isaiah lii.8. Eye contact attested from 1953. To have (or keep) an eye on "keep under supervision" is attested from early 15c. To have eyes for "be interested in or attracted to" is from 1736; make eyes at in the romance sense is from 1837; gleam in (someone's) eye (n.) "barely formed idea" is from 1959. Eye-biter was an old name for "a sort of witch who bewitches with the eyes."