Found 2 items, similar to superfetation.
English → English (WordNet) Definition: superfetation superfetation n : fertilization of a second ovum after a pregnancy has begun; results in two fetuses of different ages in the uterus at the same time; “superfetation is normal in some animal species”
English → English (gcide) Definition: Superfetation Superfetation \Su`per*fe*ta"tion\, n. [Cf. F. superf['e]tation.] (Physiol.) The formation of a fetus at the result of an impregnation occurring after another impregnation but before the birth of the offspring produced by it. This is possible only when there is a double uterus, or where menstruation persists up to the time of the second impregnation. [1913 Webster] In then became a superfetation upon, and not an ingredient in, the national character. --Coleridge. [1913 Webster]