Where does “ferm” come from?

ferm (Old Occitan) comes from Latin firmus, from Proto-Italic fermos, from Proto-Indo-European dʰer-mo-s, from Proto-Indo-European dʰer- — to support; to hold.

Ancestry of “ferm”, step by step

StepLanguageWordMeaning
1Latinfirmusstable, strong, firm; faithful, steadfast, true
2Proto-Italicfermos—
3Proto-Indo-Europeandʰer-mo-sholding
4Proto-Indo-Europeandʰer-to support; to hold
Every word from Proto-Indo-European dʰer- →Every word from Proto-Indo-European dʰer-mo-s →Every word from Proto-Italic fermos →