From PIE *h₁widh- (to separate) — literally 'the separated one,' virtually unchanged across IE for 6,000 years.
A woman whose spouse has died and who has not remarried.
From Old English 'widewe,' from Proto-Germanic *widuwō, from PIE root *h₁widʰ- (to separate, to divide, to be without). The original sense is 'the separated one' — one who has been divided from her husband by death. The PIE root *h₁widʰ- also underlies Latin 'viduus' (bereft, deprived, widowed) and its derivative 'vidua' (widow), from which French 'veuve' and Italian 'vedova' descend. Sanskrit 'vidhavā' (widow) is a direct cognate, showing
The word 'widow' is one of the best examples of PIE reconstruction. The cognates are so well preserved across languages — Sanskrit 'vidhavā,' Latin 'vidua,' Old Irish 'fedb,' Old Church Slavonic 'vĭdova,' Gothic 'widuwo,' English 'widow' — that linguists can reconstruct the PIE form *h₁widʰewh₂ with unusual confidence. The word has survived for at least 6,000 years with its meaning virtually unchanged.