From Latin 'dos' (a gift), from 'dare' (to give) — literally 'what is given,' the property accompanying a bride.
An amount of property or money brought by a bride to her husband on their marriage; a talent or quality regarded as a natural gift.
From Anglo-Norman douarie, from Medieval Latin dōtārium, from Latin dōs (genitive dōtis, a dowry, marriage portion, gift), from dare (to give), from PIE *deh₃- (to give). The full chain: PIE *deh₃- → Latin dare → dōs → Medieval Latin dōtārium → Anglo-Norman douarie → Middle English dowarie → dowry. A dowry is literally 'what is given' — the property, goods, or money a bride's family conveyed to the groom or to the new household at marriage. In Roman law the dōs was a formal legal institution
English has two related words that are often confused: 'dowry' (property the bride brings to the husband's family) and 'dower' (property the husband settles on the wife, for her support if he dies). Both derive from the same Latin root, but they describe transfers in opposite directions. The distinction was legally important in medieval and early modern property law