Lunule
Lunule , noun
[French, from Latin lunula, dim. of luna moon.]
1.
(Anatomy) Anything crescent-shaped; a crescent-shaped part or mark; a lunula; a lune.
2.
(Chemistry) A lune. See Lune.
3.
(a) (Zoology) A small or narrow crescent.
(b)
(Zoology) A special area in front of the beak of many bivalve shells. It sometimes has the shape of a double crescent, but is oftener heart-shaped. See Illust. of Bivalve.