means A woman whose spouse has died and who has not remarried.

from From Old English 'widewe,' tracing back to the Proto-Indo-European root *widhewo-, meaning 'bereft' or 'separated' — the same ancient sense of being split apart that also gives Latin 'vidua,' Sanskrit 'vidhava,' and the 'divide' family. So at its root the word doesn't describe the marriage that was, but the wrenching apart that ended it. The black widow spider borrowed the name in the 19th century for the female's grim habit of devouring her mate.