a black bow tie, worn with a dinner jacket.
semiformal evening wear for men (distinguished from white tie
black-tiePronunciation: (blak'tī'), [key]
requiring that guests wear semiformal attire, esp. that men wear black bow ties with tuxedos or dinner jackets: a black-tie dance.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.