Where does “setenbro” come from?

setenbro (Old Portuguese) comes from Latin september, from Latin Septem, from Proto-Italic septem, from Proto-Indo-European septḿ̥ — seven.

Ancestry of “setenbro”, step by step

StepLanguageWordMeaning
1Latinseptemberof September
2LatinSeptemseven; 7
3Proto-Italicseptemseven
4Proto-Indo-Europeanseptḿ̥seven
Every word from Proto-Indo-European septḿ̥ →Every word from Proto-Italic septem →Every word from Latin Septem →