n.formalwear consisting of full evening dress for men
同义词：dress suitfull dresstailcoattail coattailswhite tiewhite tie and tails
英汉双解大词典
tailcoat/ˈteɪlkəʊt/(alsotailcoat)
1.
N-COUNT（可数名词）
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. 燕尾服