Source : Webster's Revised Unabridged Dictionary (1913)

Lingual \Lin"gual\, n.
   A consonant sound formed by the aid of the tongue; -- a term
   especially applied to certain articulations (as those of t,
   d, th, and n) and to the letters denoting them.

   Note: In Sanskrit grammar certain letters, as [.t], [.t]h,
         [dsdot], [dsdot]h, [.n], are called linguals,
         cerebrals, or cacuminals. They are uttered with the tip
         of the tongue turned up and drawn back into the dome of
         the palate.

Lingual \Lin"gual\ (l[i^][ng]"gwal), a. [L. lingua tongue: cf.
   F. lingual. See {Tongue}, and cf. {Language}.]
   Of or pertaining to the tongue; uttered by the aid of the
   tongue; glossal; as, the lingual nerves; a lingual letter.

   {Lingual ribbon}. (Zo["o]l.) See {Odontophore}.

Source : WordNet®

lingual
     adj 1: consisting of or related to language; "linguistic behavior";
            "a linguistic atlas"; "lingual diversity" [syn: {linguistic}]
            [ant: {nonlinguistic}]
     2: pertaining to or resembling or lying near the tongue;
        "lingual inflammation"; "the lingual surface of the teeth"