The Collaborative International Dictionary of English v.0.48:

Lingual \Lin"gual\ (l[i^][ng]"gwal), a. [L. lingua tongue: cf.
   F. lingual. See Tongue, and cf. Language.]
   1. Of or pertaining to the tongue; uttered by the aid of the
      tongue; glossal; as, the lingual nerves; a lingual letter.
      [1913 Webster]

   2. lying near the tongue; especially, in dentistry, on the
      surface of the tooth next to the tongue. Contrasted with
      buccal, the side of a tooth touching the cheek, i. e.
      the side opposite to the lingual side.
      [PJC]

   Lingual ribbon. (Zool.) See Odontophore.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Radula \Rad"u*la\ (r[a^]d"[-u]*l[.a]), n.; pl. Radulae
   (r[a^]d"[-u]*l[=e]). [L., a scraper, fr. radere to scrape.]
   (Zool.)
   The chitinous ribbon bearing the teeth of mollusks; -- called
   also lingual ribbon, and tongue. See Odontophore.
   [1913 Webster]