Where does “ratoeira” come from?

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

ratoeira (Portuguese): mousetrap device for killing mice

Definitions

mousetrap device for killing mice

Ancestry of “ratoeira”, step by step

Step	Language	Word	Meaning
1	Portuguese	-eira	female equivalent of -eiro; feminine of -eiro
2	Old Portuguese	-eira	—
3	Latin	-āria	used to form feminine counterparts of masculine agent nouns in
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 Latin -āria →