Dem"i*lune` (?), n. [F. demi-lune.]
1. Fort.
A work constructed beyond the main ditch of a fortress, and in front of the curtain between two bastions, intended to defend the curtain; a ravelin. See Ravelin.
2. Physiol.
A crescentic mass of granular protoplasm present in the salivary glands.
⇒ Each crescent is made of polyhedral cells which under some circumstances are supposed to give rise to new salivary cells.
© Webster 1913.