1. <pathology> Growth, usually benign, protruding from a mucous membrane.

2. <plant biology> The sessile stage of the Cnidarian life cycle, the cylindrical body is attached to the substratum at its lower end and has a mouth surrounded by tentacles bearing nematocysts at the upper end, Hydra and the feeding polyps of the colonial Obelia are examples.

(14 Oct 1997)