one-piece
noun [ C ] uk/ˈwʌn.piːs/ us/ˈwʌn.piːs/ (US usually one-piece swimsuit)
一件式泳装，连体泳衣
a piece of women's clothing that is worn when swimming or on a beach and consists of a single piece of material rather than a separate top and bottom
I'd prefer a one-piece to a bikini. 跟比基尼相比，我更喜欢连体式泳装。