Where does “-êra” come from?

-êra (Macanese) comes from Old Portuguese -eira, from Latin -āria, from Latin -ārius, from Proto-Italic *-āzios — Forms relational adjectives to nouns (and rarely numerals).

Ancestry of “-êra”, step by step

Step	Language	Word	Meaning
1	Old Portuguese	-eira	—
2	Latin	-āria	used to form feminine counterparts of masculine agent nouns in
3	Latin	-ārius	er
4	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 Latin -āria →