-eiro

Meaning

1. (masculine, morpheme) forms nouns from nouns or verbs, denoting someone who works with the suffixed noun or engages in the suffixed verb; -er; -eer
2. (masculine, morpheme) forms nouns, from nouns denoting a location or type of location, meaning “someone from the location” and adjectives meaning “of, from or related to the location”
3. (masculine, morpheme) forms nouns from the names of fruits or other plant products, denoting the plant bearing them, usually trees and shrubs
4. (masculine, morpheme) forms nouns, from nouns, denoting a container or a place where there is plenty of the suffixed noun

Etymology

Inherited from Latin: -ārius

Cognate with Portuguese: -eiro

Cognate with Spanish: -ero

In summary

From Old Galician-Portuguese -eiro, from Latin -ārius and -ārium, with metathesis of "i" (through a Vulgar Latin form *-airu). Compare Portuguese -eiro, Spanish -ero.