A sailing boat with three hulls: one main hull in the middle and a smaller float on each side. The two outer floats keep it from tipping over, so a trimaran can carry a big sail and go very fast without needing heavy weight underneath like an ordinary yacht. It is also steady and roomy, which is why you see them used for racing and for long ocean crossings. Compare catamaran, which has two hulls — that is the far more common word, and the one the ferry you take is likely to be. The three-hulled kind is rarer, so trimaran mostly appears in sailing talk, boat shows and news about record-breaking voyages. Countable noun: a trimaran, two trimarans. Say it TRY-muh-ran.

三體船（三個船身的帆船；兩側各有一個小浮體）。跟雙體船 catamaran 相對。