purify (v.)

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.

late 14c., purificacioun, "ritual purification, a cleansing of the soul from guilt or defilement," originally especially in reference to the Feast of the Purification of the Virgin Mary, from Old French purificacion, from Latin purificationem (nominative purificatio) "a purifying," noun of action from past-participle stem of purificare "to make pure" (see purify). General sense of "a freeing from dirt or defilement" is from 1590s.