means A garment worn for swimming, designed to cling, dry fast, and stay put in the water.

from A transparent compound of "swim" and "suit." "Swim" descends from Old English "swimman," the verb for moving through water, with Germanic cousins across the North Sea. "Suit" came through Anglo-French "siwte" from Latin "sequi," "to follow" — a suit being a set of things that go together. The pairing is modern, riding the rise of public bathing and seaside leisure, when swimming demanded its own purpose-built outfit rather than ordinary clothes; older terms like "bathing costume" and "bathing suit" came first.