Where does “airiseamh” come from?

airiseamh (Irish) comes from Irish -amh, from Old Irish -em, from Proto-Celtic *-īmā.

Ancestry of “airiseamh”, step by step

StepLanguageWordMeaning
1Irish-amhforms verbal nouns
2Old Irish-emForms occupational nouns
3Proto-Celtic*-īmā—
Every word from Proto-Celtic *-īmā →Every word from Old Irish -em →Every word from Irish -amh →