in loco parentis

(plural loci), 1715, "place, spot, locality," from Latin locus "a place, spot; appointed place, position; locality, region, country; degree, rank, order; topic, subject," from Old Latin stlocus, a word of uncertain origin. Used by Latin writers for Greek topos. Mathematical sense by 1750.

early 15c. (late 12c. as a surname), "a mother or father; a forebear, ancestor," from Old French parent "father, parent, relative, kin" (11c.) and directly from Latin parentem (nominative parens) "father or mother, ancestor," noun use of present participle of parire "bring forth, give birth to, produce," from PIE root *pere- (1) "to produce, bring forth." Began to replace native elder after c. 1500.