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.
Definition of concave. 1  1 : hollowed or rounded inward like the inside of a bowl a concave lens. 2  2 : arched in : curving in âused of the side of a curve or surface on which neighboring normals to the curve or surface converge and on which lies the chord joining two neighboring points of the curve or surface.