Source : Webster's Revised Unabridged Dictionary (1913)

Radula \Rad"u*la\, n.; pl. {Radul[ae]}. [L., a scraper, fr.
   radere to scrape.] (Zo["o]l.)
   The chitinous ribbon bearing the teeth of mollusks; -- called
   also {lingual ribbon}, and {tongue}. See {Odontophore}.