encounter (n.)

c. 1300, "meeting of adversaries, confrontation," from Old French encontre "meeting; fight; opportunity" (12c.), noun use of preposition/adverb encontre "against, counter to" from Late Latin incontra "in front of," from Latin in- "in" (from PIE root *en "in") + contra "against" (see contra (prep., adv.)). Modern use of the word in psychology is from 1967, from the work of U.S. psychologist Carl Rogers. Encounter group attested from 1967.

c. 1300, "to meet as an adversary," from Old French encontrer "meet, come across; confront, fight, oppose," from encontre "a meeting; a fight; opportunity" (12c.), noun use of preposition/adverb encontre "against, counter to" from Late Latin incontra "in front of," from Latin in-"in" (from PIE root *en "in") + contra "against" (see contra). Weakened sense of "meet casually or unexpectedly" first recorded in English early 16c. Related: Encountered; encountering.