Wiktionary
n. A type of cannibalism in animals, whereby the female devours the male after, or during, copulation.
Wikipedia
Sexual cannibalism is when a female cannibalizes her mate prior to, during, or after copulation. It is a phenomenon characterized primarily by members of most arachnid orders, as well as several insect orders. The adaptive foraging hypothesis, aggressive spillover hypothesis and mistaken identity hypothesis are among the proposed theories to explain how sexual cannibalism evolved. This behavior is believed to have evolved as a manifestation of sexual conflict, occurring when the reproductive interests of males and females differ. In many species that exhibit sexual cannibalism, the female consumes the male upon detection. Females of cannibalistic species are generally hostile and unwilling to mate; thus many males of these species have developed adaptive behaviors to counteract female aggression.
Usage examples of "sexual cannibalism".
At this point I shall mention just one example, a behavior that at first seems diametrically opposed to evolutionary logic: sexual cannibalism.