Also found in: Medical.
Having three costae.
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.
(Biology) biology having three ribs or riblike parts: tricostate leaves.
[C19: from tri- + costate]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
tri•cos•tate(traɪˈkɒs teɪt, -ˈkɔ steɪt)
(of a plant or animal) having three ribs, costae, or raised lines.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.