tailcoat

US /ˈteɪl.koʊt/
UK /ˈteɪl.koʊt/
"tailcoat" picture
1.

a man's formal coat, black or dark blue, with a long skirt divided into two tails at the back, worn for formal evening occasions.

:
He looked very distinguished in his black tailcoat.
The orchestra members wore tailcoats for the concert.