Added 10 October 2026 biconcave adjective Categories: Describing WordsRare Words adjective ! Definition from Wiktionary (CC BY-SA). More about biconcave at Wordnik → Where our words come from → Having both sides that are concave. a biconcave lens Related Words: concaveconcavo-concaveconcavo-convexbiconvexconcavoconvexplanoconcaveconcavoconcaveplanoconvexconvexoconvexamphicoelousconvexoconcave Back to today's word