Source : Webster's Revised Unabridged Dictionary (1913)

Lambda \Lamb"da\, n. [NL., fr. Gr. ?.]
   1. The name of the Greek letter [Lambda], [lambda],
      corresponding with the English letter L, l.

   2. (Anat.) The point of junction of the sagittal and lambdoid
      sutures of the skull.

   {Lambda moth} (Zo["o]l.), a moth so called from a mark on its
      wings, resembling the Greek letter lambda ([Lambda]).