concavo-convex
a. ஒருபுறம் உட்குழிந்து மறுபுறம் வௌதக்குவிவான.
Con*ca`vo-con"vex, a. 1. Concave on one side and convex on the other, as an eggshell or a crescent. 2. (Optics) Defn: Specifically, having such a combination of concave and convex sides as makes the focal axis the shortest line between them. See Illust. under Lens.