Source : Webster's Revised Unabridged Dictionary (1913)

Ligula \Lig"u*la\ (l[i^]g"[-u]*l[.a]), n.; pl. L. {Ligul[ae]}
   (-l[=e]), E. {Ligulas} (-l[.a]z). [L., a little tongue. See
   {Ligule}.]
   1. (Bot.) See {Ligule}.

   2. (Zo["o]l.)
      (a) The central process, or front edge, of the labium of
          insects. It sometimes serves as a tongue or proboscis,
          as in bees. [See Illust. under {Labium}, and
          {Hymenoptera}.]
      (b) A tongue-shaped lobe of the parapodia of annelids. See
          {Parapodium}.

Source : WordNet®

ligulae
     See {ligula}