butyl n.

Old English butere "butter, the fatty part of milk," obtained from cream by churning, general West Germanic (compare Old Frisian, Old High German butera, German Butter, Dutch boter), an early loan-word from Latin butyrum "butter" (source of Italian burro, Old French burre, French beurre), from Greek boutyron. This is apparently "cow-cheese," from bous "ox, cow" (from PIE root *gwou- "ox, bull, cow") + tyros "cheese" (from PIE root *teue- "to swell"); but this might be a folk etymology of a Scythian word.

The product was used from an early date in India, Iran and northern Europe, but not in ancient Greece and Rome. Herodotus described it (along with cannabis) among the oddities of the Scythians. In old chemistry, applied to certain substances of buttery consistency. Butter-knife, a small, dull knife used for cutting butter at the table, is attested from 1818.

paraffin hydrocarbon, 1875, from butyl, hydrocarbon from butyric acid, a product of fermentation found in rancid butter, from Latin butyrum (see butter (n.)) + chemical suffix -ane.

Proto-Indo-European root meaning "ox, bull, cow," perhaps ultimately imitative of lowing; compare Sumerian gu, Chinese ngu, ngo "ox."

It forms all or part of: beef; Boeotian; Bosphorus; boustrophedon; bovine; bugle; Bucephalus; bucolic; buffalo; bugloss; bulimia; butane; butter; butyl; butyric; cow (n.); cowbell; cowboy; cowlick; cowslip; Euboea; Gurkha; hecatomb; kine.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit gaus, Greek bous, Latin bos, Old Irish bo, Latvian guovs, Armenian gaus, Old English cu, German Kuh, Old Norse kyr, Slovak hovado "cow, ox."

In Germanic and Celtic, of females only; in most other languages, of either gender. For "cow" Latin uses bos femina or vacca, a separate word of unknown origin. Other "cow" words sometimes are from roots meaning "horn, horned," such as Lithuanian karvė, Old Church Slavonic krava.