c. 1300, paren, "peel (fruit), cut off the crust (of bread)," from Old French parer "arrange, prepare; trim, adorn," and directly from Latin parare "make ready, prepare, furnish, provide, arrange, order; contrive, design, intend, resolve; procure, acquire, obtain, get; get with money, buy, purchase" (related to parire "produce, bring forth, give birth to"), from PIE *par-a-, suffixed form of root *pere- (1) "to produce, procure."
From late 14c. in the more general sense of "trim by cutting or scraping off an outer layer;" meaning "to reduce something little by little" is from 1520s. Pare down "reduce by cutting or striking off" is from late 15c. Related: Pared; paring.