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concavo-concave

American  
[kon-key-voh-kon-keyv] / kɒnˈkeɪ voʊ kɒnˈkeɪv /

adjective

  1. concave on both sides.


concavo-concave British  
/ kɒnˌkeɪvəʊkɒnˈkeɪv /

adjective

  1. (esp of a lens) having both sides concave; biconcave

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of concavo-concave

< Latin concav ( us ) + -o- + concave