ca·lyx (k??l?ks, k?l??ks)n. pl. ca·ly·ces (k??l?-s?z?, k?l??-) also ca·lyx·es 1. Botany The outermost part of a flower, consisting of the sepals.2. Anatomy A cuplike structure, such as the collecting structures into which the pelvis of the kidney is divided.3. Ecclesiastical A calix.[Latin calyx, calyc-, from Greek kalux.]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.calyx (?ke?l?ks; ?kæl?ks) n, pl calyxes or calyces (?kæl??si?z; ?ke?l?-) 1. (Botany) the sepals of a flower collectively, forming the outer floral envelope that protects the developing flower bud. Compare corolla2. (Anatomy) any cup-shaped cavity or structure, esp any of the divisions of the human kidney (renal calyx) that form the renal pelvis[C17: from Latin, from Greek kalux shell, from kaluptein to cover, hide] calycate adjCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014ca?lyx (?ke? l?ks, ?kæl ?ks) n., pl. ca?lyx?es, cal?y?ces (?kæl ??siz, ?ke? l?-) 1. the outermost group of floral parts; the sepals collectively. 2. Anat., Zool. a cuplike part. [1665?75;