"three successive lines rhyming together," 1590s, from Italian terzetto, diminutive of terzo "third," from Latin tertius (see third). Spelling influenced by French tercet, from the Italian.
old unit of liquid measure equal to one-third of a pipe (42 gallons), 1530s, from Anglo-French ters, Old French tierce (11c.). used in the sense "one-third" in various ways, from Latin tertia, fem. of tertius "a third," from PIE *tri-tyo-, from root *trei- (see three). Also used in Middle English for "a third part" (late 15c.), "the third hour of the canonical day" (ending at 9 a.m.), late 14c., and, in astronomy and geometry, "sixtieth part of a second of an arc."
one of the three districts, anciently under the government of a reeve, into which Yorkshire was divided, late 13c., from late Old English *þriðing, a relic of Viking rule, from Old Norse ðriðjungr "third part," from ðriði "third" (see third).
The initial consonant apparently was merged by misdivision with final consonant of preceding north, west, or east.
also buck-eye, "American horse-chestnut tree," 1763, said to be so called from resemblance of the nut to a stag's eye (see buck (n.1) + eye (n.)). Meaning "native of Ohio" is attested since 1822, from the great number of such trees growing there. Used figuratively in early 20c. of anything cheap or inferior.
c. 1500, "of or pertaining to the eye," from Late Latin ocularis "of the eyes," from Latin oculus "an eye," from PIE root *okw- "to see." As a noun, "eyepiece of an optical instrument," 1835, from the adjective.
often double whammy, "hex, evil eye," 1932, of unknown origin, popularized 1941 in Al Capp's comic strip "Li'l Abner," where it was the specialty of Evil-Eye Fleegle.