superfetation definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
the fertilization of an ovum during a pregnancy already in existence
Origin: Midieval Latin superfetatio ; from Classical Latin superfetatus, past participle of superfetare ; from super- (see super-) plush fetare, to bring forth, impregnate ; from fetus, fetus
superfetation definition by American Heritage Dictionary
Formation or development of a second fetus when one is already present in the uterus, occurring normally in some animal species.