lingual (adj.)

"of or pertaining to the tongue," 1640s, from Medieval Latin lingualis "of the tongue," from Latin lingua "tongue," also "speech, language," from Old Latin dingua, from PIE *dnghu- "tongue" (source also of Old English tunge "tongue;" see tongue (n.)). Altered in Latin probably in part by association with lingere "to lick." Earlier "tongue-shaped" (c. 1400).