Pure
Middle English: from Old French pur ‘pure’, from Latin purus .
wiktionary
From Middle English pure, pur, from Old French pur, from Latin pūrus(“clean, free from dirt or filth, unmixed, plain”), from Proto-Indo-European *pewH-(“to cleanse, purify”). Displaced native Middle English lutter(“pure, clear, sincere”) (from Old English hlūtor, hluttor), Middle English skere(“pure, sheer, clear”) (from Old English scǣre and Old Norse skǣr), Middle English schir(“clear, pure”) (from Old English scīr), Middle English smete, smeate(“pure, refined”) (from Old English smǣte; compare Old English mǣre(“pure”)).
pure ( uncountable)
etymonline
pure (adj.)
mid-13c., of gold, "unalloyed;" c. 1300 "unmixed, unadulterated; homogeneous," also "total, complete, absolute; bare, mere," also "sexually pure, virgin, chaste" (late 12c. as a surname, and Old English had purlamb "lamb without a blemish"), from Old French pur "pure, simple, absolute, unalloyed," figuratively "simple, sheer, mere" (12c.), from Latin purus "clean, clear; unmixed; unadorned; chaste, undefiled."
This is conjectured to be from PIE root *peue- "to purify, cleanse" (source also of Latin putus "clear, pure;" Sanskrit pavate "purifies, cleanses," putah "pure;" Middle Irish ur "fresh, new;" Old High German fowen "to sift").
It replaced Old English hlutor. The meaning "free from moral corruption" is recorded from mid-14c. In reference to bloodlines, attested from late 15c. In music, "mathematically perfect," by 1872.
