Definitions for: Involucrum

Webster (1913) Definition: In`vo*lu"crum, n.; pl. L. Involucra, E.
Involucrums. [L. See Involucre.]
1. (Bot.) See Involucre.

2. (Zo["o]l.) A sheath which surrounds the base of the lasso
cells in the Siphonophora.