Lingo

google

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mid 17th century: probably via Portuguese lingoa from Latin lingua ‘tongue’.

wiktionary

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From Latin lingua(“language”) + -o(diminutive suffix).

etymonline

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lingo (n.)

"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.