Fishwife

A fishwife, fish-fag or fishlass is a woman who sells fish. She is typically the wife of a fisherman, selling her husband's catch, but other sources of fish have been used.
Some wives and daughters of fishermen were notoriously loud and foul-mouthed, as noted in the expression, To swear like a fishwife as they sold fish in the marketplace. Among the reasons for their outspokenness were that their wares were highly perishable and lost value if not sold quickly,... meer