From Proto-Italic *wiðowā, Proto-Indo-European *h₁widʰéwh₂. Cognates include Sanskrit विधवा (vidhávā), Ancient Greek ἠΐθεος (ēḯtheos), Proto-Slavic *vьdova and Old English widuwe (English widow).
Practice speaking and memorizing "vidua" and many other words and sentences in Latin.