"foreign speech," 1650s, probably a corruption of Latin lingua "speech, language; tongue" (from PIE root *dnghu- "tongue"), perhaps immediately as a shortening of lingua franca (q.v.), or from Provençal lingo "language, tongue," from Old Provençal lenga, from Latin lingua.
they don't speak our lingo
-ling
lingam
linger
lingerie
lingering
lingo
lingua franca
lingual
Linguaphone
linguiform
linguine