‖Co″ma, n. [L., hair, fr. Gr. κόμη.] 1. (Astron.) The envelope of a comet; a nebulous covering, which surrounds the nucleus or body of a comet.
2. (Bot.) A tuft or bunch, — as the assemblage of branches forming the head of a tree; or a cluster of bracts when empty and terminating the inflorescence of a plant; or a tuft of long hairs on certain seeds.
Coma Berenices (�) (Astron.), a small constellation north of Virgo; — called also Berenice's Hair.