[1] : The Collaborative International Dictionary of English v.0.48

labellum \label"lum\ l.abe^l"lu^m, n.; pl. l.
   labella l.abe^l"l.a, e. labellums
   l.abe^l"lu^mz. l., dim. of labrum lip.
   1. bot. the lower or apparently anterior petal of an
      orchidaceous flower, often of a very curious shape.
      1913 webster

   2. zool. a small appendage beneath the upper lip or labrum
      of certain insects.
      1913 webster
see also:
labella labellums 

Labellum >> L Words
Labellum, definition of term: Labellum
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