'Tongue' and 'language' are distant cousins — both from PIE *dnghweh-s. Latin 'lingua' was once 'dingua.'
The fleshy muscular organ in the mouth, used for tasting, licking, swallowing, and (in humans) articulating speech.
From Old English tunge, from Proto-Germanic *tungō, from PIE *dn̥ǵʰwéh₂s (tongue). This is one of the most securely reconstructed body-part terms in comparative linguistics, with reflexes in virtually every branch of Indo-European: Latin lingua (via an older *dingua), Sanskrit jihvā́, Old Irish tengae, Lithuanian liežùvis, Old Church Slavonic językŭ, and Tocharian B kantwo. The PIE form shows a dental stop *d-, a nasal infix, and