tuxedo UK /tʌkˈsiːdəʊ/US /tʌkˈsidoʊ/ noun3 •A typically black formal jacket worn by men.He wore a tuxedo for his sister's wedding.His mom bought a tuxedo for him. •The entire suit complementing and including this jacket. •Ellipsis of tuxedo cat. formstuxedoes · tuxedos