N-COUNT （男子在正式场合穿的）燕尾服，晚礼服 A tailcoat is a man's coat which is short at the front with long pieces at the back. Tailcoats were popular in the 19th century and are now worn only for very formal occasions, such as weddings. （男子在正式场合穿的）燕尾服，晚礼服