Where does “-our” come from?

-our (Middle English) comes from Old French -eor, from Latin -ator, from Latin -tor, from Proto-Italic -tōr, from Proto-Indo-European -tōr, from Proto-Indo-European -tor-s.

Ancestry of “-our”, step by step

Step	Language	Word	Meaning
1	Old French	-eor	Alternative form of -or
2	Latin	-ator	-ator, -er; second-person singular future passive...
3	Latin	-tor	-er
4	Proto-Italic	-tōr	Forms agent nouns to verb stems
5	Proto-Indo-European	-tōr	Derives agent nouns from verbs, denoting someone...
6	Proto-Indo-European	-tor-s	—

Words derived from “-our”

Every word from Proto-Indo-European -tor-s →Every word from Latin -tor →Every word from Old French -eor →