1. (Zoology) either of a pair of sensory appendages that arise from the mouthparts of crustaceans and insects. 2. (Zoology) either of a pair of tactile organs arising from the head or anterior end of certain annelids and molluscs. [C19: from French, from Latin palpus a touching]
Convex, meaning curving out or extending outward (compare concave), may refer to: Convex set in mathematics Convex function in mathematics convex polygon a polygon in which no line segment between two points on the boundary ever goes outside the polygon.
Concave is an adjective describing a surface that curves inward, like the inner surface of a sphere. Its antonym, convex, describes a surface that curves outward, like the exterior of a sphere. In geometry, concave and convex refer to polygons. A concave polygon has at least one angle greater than 180 degrees.