the.com/black widow

means A glossy black spider whose venomous bite is medically dangerous to humans, named for the female's habit of sometimes eating the male after mating.

from The name is 19th/early 20th-century English, built straightforwardly from 'widow' — a woman whose spouse has died — applied to the spider because females were observed consuming their mates, making themselves, biologically speaking, widows by their own hand. The behavior is real but overstated by legend: cannibalism happens more often in captivity or under observation stress than in the wild, and plenty of males survive mating entirely. The name stuck anyway, because a murderous bride is a far better story than a shy arachnid who usually just wants to be left alone.