泳衣 (yǒng yī) literally combines 泳 (yǒng), meaning 'to swim', and 衣 (yī), meaning 'clothing' — together, it means 'swimsuit', the garment worn for swimming or water-related activities. It is a compound noun formed by combining an action verb and a general clothing term, following a common Chinese pattern where the first character indicates function or purpose.

This word is used in everyday contexts such as buying swimwear, preparing for a beach trip, or discussing pool safety rules. 泳衣 can refer to any type of swimsuit — one-piece, bikini, trunks, or even competitive racing suits — though context usually clarifies the style. It’s neutral in register and appropriate for both spoken and written Chinese, commonly appearing in advertisements, travel guides, and fitness instructions.