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n. A man's black coat worn for formal daytime occasions and having a long rounded and split tail. Also called swallowtail, swallow-tailed coat.

n. A formal evening jacket with an extended back panel; a dress coat.

n. Any coat with similar tails.

n. formalwear consisting of full evening dress for men

"The infamous photo of Dave posing alongside his posho chums from the Bullingdon Club in an expensive royal blue tailcoat is one of the few clues we have."

formalwear    evening clothes    eveningwear    evening dress   

hanging on his / her coat tails    tails   

oldie    jabot    weepers    breastknot    tarboosh    chapeau    languishment    obi    half-staff    shite