seg·re·gant (s?g?r?-g?nt) Genetics adj. Differing from either parent as a result of segregation: a segregant genotype.n. A segregant type or organism. Also called segregate.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.segregant (?s??r???nt) geneticsnan organism which is different because of segregationadjdiffering from a parent because of segregationCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014