Welsh erw

← Breton erv (cognate)

← Proto-Celtic *arwī (inherited)

← Proto-Indo-European *h₂erh₃- (root)

← Proto-Indo-European *h₂erh₃- (inherited)

← Cornish erow (cognate)

← Latin arvum (cognate)

← Old Irish arbor (cognate)

→ English erw (borrowed)

→ Breton erv (cognate)

→ Welsh erwau (affix)

→ Ancient Greek ἔραζε (cognate)