Where does “-is” come from?

-is (Irish) comes from Old Irish -as, from Proto-Celtic -assus, from Proto-Indo-European -ad-tus.

-is (Irish): -ish, -ese; inflection of -eas: ##...

Definitions

  1. -ish, -ese; inflection of -eas: ##...

Ancestry of “-is”, step by step

StepLanguageWordMeaning
1Old Irish-asNominal suffix, used to form abstract ideas or...
2Proto-Celtic-assus—
3Proto-Indo-European-ad-tus—

Words derived from “-is”

Every word from Proto-Indo-European -ad-tus →Every word from Old Irish -as →Every word from Proto-Celtic -assus →
-is — Etymology, Origin & Word History | Etymology Explorer