"to communicate (with)," 1590s; earlier "to move about, live, dwell" (mid-14c.), from Old French converser "to talk" (12c.), from Latin conversari (see conversation). Related: Conversed; conversing.
"exact opposite," 1560s, from Latin conversus "turn around," past participle of convertere "to turn about" (see convert). Originally mathematical. The noun is attested from 1550s in mathematics. Related: Conversely.