Where does “aithiseoir” come from?

aithiseoir (Irish) comes from Irish -óir, from Old Irish -óir, from Proto-Brythonic -ọr, from Latin -ārius, from Proto-Italic *-āzios — Forms relational adjectives to nouns (and rarely numerals).

aithiseoir (Irish): defamer, denigrator, traducer, vilifier

Definitions

defamer, denigrator, traducer, vilifier

Ancestry of “aithiseoir”, step by step

Step	Language	Word	Meaning
1	Irish	-óir	-er; suffix appended to words to create an agent...
2	Old Irish	-óir	er, -or
3	Proto-Brythonic	-ọr	—
4	Latin	-ārius	er
5	Proto-Italic	*-āzios	Forms relational adjectives to nouns (and rarely numerals)

Every word from Proto-Italic *-āzios →Every word from Latin -ārius →Every word from Irish -óir →