sexual selectionn. Biology The process in nature by which individuals with certain traits, especially secondary sex characteristics such as colorful plumage and large antlers, are chosen more often for mating and thus pass those traits on to their offspring.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.sexual selection n (Zoology) an evolutionary process in animals, in which selection by females of males with certain characters, such as large antlers or bright plumage, results in the preservation of these characters in the species Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014sex?ual selec?tion n. the Darwinian theory that the selection of mates is based on attractive features, as coloration or song in birds. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.