bi·con·vex
(bī′kŏn-vĕks′, bī-kŏn′vĕks′)adj.
Convex on both sides or surfaces: a biconvex disk.
bi′con·vex′i·ty (-vĕk′sĭ-tē) n.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
biconvexity
(ˌbaɪkənˈvɛksɪtɪ)n
the characteristic of having two convex surfaces
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014