re·di·a (r??d?-?)n. pl. re·di·ae (-d?-??) A larva of certain trematodes that is produced within the sporocyst and that can give rise to additional rediae or to cercariae.[New Latin, after Francesco Redi (1626-1697), Italian naturalist.]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.redia (?ri?d??) n, pl -diae (-d??i?) (Animals) a parasitic larva of flukes that has simple locomotory organs, pharynx, and intestine and gives rise either to other rediae or to a different larva (the cercaria)[C19: from New Latin, named after Francesco Redi (1629?97), Italian naturalist]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014re?di?a (?ri di ?) n., pl. -di?ae (-di?i) a cylindrical larva in some trematodes that is produced by a sporocyst and gives rise to daughter rediae or cercariae. [1875?80;