Portuguese dono, Catalan don, French dom, Italian don, Aromanian domnu, Romanian domn
Sanskrit dámūnas- "lord of the house"
Cf. Basque dono- "saint," "holy," found in toponyms (e.g., Donostia), and was borrowed from Vulgar Latin *domnus "lord." Thus, dono- entered Basque during Latin's evolution into the Romance languages.