Where does “don” come from?

don (Old Portuguese) comes from Latin donum, from Proto-Italic dōnom, from Proto-Indo-European déh₃nom, from Proto-Indo-European deh₃- — to give.

Ancestry of “don”, step by step

StepLanguageWordMeaning
1Latindonumgift, present; offering, sacrifice
2Proto-Italicdōnomgift, present
3Proto-Indo-Europeandéh₃nomgift
4Proto-Indo-Europeandeh₃-to give
Every word from Proto-Indo-European deh₃- →Every word from Proto-Indo-European déh₃nom →Every word from Proto-Italic dōnom →