Words related to *kwetwer-

cadre (n.)
"permanently organized framework of a military unit" (the officers, etc., as opposed to the rank-and-file), 1851; earlier "framework, scheme" (1830); from French cadre, literally "a frame of a picture" (16c.), so, "a detachment forming the skeleton of a regiment," from Italian quadro, from Latin quadrum "a square," which related to quattuor "four" (from PIE root *kwetwer- "four"). The communist sense "group or cell of workers trained to promote the interests of the Party" is from 1930.
cahier (n.)
"exercise book; report of proceedings," c. 1845, "book of loose sheets tacked together," from French cahier "writing book, copy-book," originally a bookbinding term, from Old French cayer, originally quaier "sheet of paper folded in four," from Vulgar Latin *quaternus, from Latin quaterni "four each," from quater "four times" (from PIE root *kwetwer- "four"). Compare quire (n.1).
carillon (n.)
"set of tuned, stationary bells sounded by means of a keyboard or other machinery," 1775, from French carillon, which, according to French sources, is from Old French carignon "set of four bells," an alteration of quarregon, from Vulgar Latin *quadrinionem, from Latin quaternionem "set of four," from quater "four times," from PIE *kwetrus, from root *kwetwer- "four."
carrefour (n.)
late 15c., "place where four ways meet," from Old French carrefor (13c., quarrefour), from Medieval Latin quadrifurcus "four-forked," from Latin quatuor "four" (from PIE root *kwetwer- "four") + furca "two-pronged fork" (a word of unknown etymology). "Formerly quite naturalized, but now treated only as French" [OED]. Englished variant carfax is from Middle English carfourkes.
catty-cornered (adj., adv.)

1838, earlier cater-cornered (1835, American English), from now-obsolete cater "to set, cut, or move diagonally" (1570s), from French catre "four," from Latin quattuor (from PIE root *kwetwer- "four"). Compare carrefour. Related: Catty-corner; cattycorner.

diatessaron (n.)

late 14c. as a term in music meaning "interval of a fourth;" 1803 in reference to harmonizings of the four gospels, especially that of Tatian (late 2c.), via Old French and Latin from Greek dia tessaron, from dia "composed of" (literally "through;" see dia-) + tessaron "four," related to tessares "the numeral four" (from PIE root *kwetwer- "four").

escadrille (n.)
1893, from French escadrille, from Spanish escuadrilla, diminutive of escuadra "square, squad, squadron," from Vulgar Latin *exquadrare, from Latin quadrare "to make square," related to quadrus "a square," quattuor "four" (from PIE root *kwetwer- "four").
farthing (n.)

Old English feorðing (Old Northumbrian feorðung) "quarter of a penny; a fourth part," a diminutive derivative of feorða "fourth" (from feower "four;" from PIE root *kwetwer- "four") + -ing "fractional part." Cognate with Old Frisian fiardeng, Middle Low German verdink, Old Norse fjorðungr, Old Danish fjerdung "a fourth part of anything."

In late Old English also a division of land, probably originally a quarter of a hide. The modern English coin first was minted under Edward I and abolished 1961. The word was used in biblical translations for Latin quadrans "quarter of a denarius."

I shall geat a fart of a dead man as soone As a farthyng of him. [Heywood, "Proverbs," 1562]
firkin (n.)
"small cask," late 14c., apparently from Middle Dutch *vierdekijn, diminutive of vierde, literally "fourth, fourth part" (from vier "four," from PIE root *kwetwer- "four"); so called because it usually is the fourth part of a barrel.
fortnight (n.)
"period of two weeks," 17c. contraction of Middle English fourteniht, from Old English feowertyne niht, literally "fourteen nights" (see fourteen + night). It preserves the ancient Germanic custom of reckoning by nights (mentioned by Tacitus in "Germania" xi). Related: Fortnightly.