The Collaborative International Dictionary of English v.0.48:

Lentil \Len"til\ (l[e^]n"t[i^]l), n. [F. lentille, fr. L.
   lenticula, dim. of lens, lentis, lentil. Cf. Lens.] (Bot.)
   A leguminous plant of the genus Ervum (Ervum Lens), of
   small size, common in the fields in Europe. Also, its seed,
   which is used for food on the continent.
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   Note: The lentil of the Scriptures probably included several
         other vetchlike plants.
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   Lentil shell (Zool.), a small bivalve shell of the genus
      Ervillia, family Tellinid[ae].
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