Define nightclub: a place of entertainment open at night usually serving food and liquor and providing music and space for — nightclub in a sentence. A nightclub, music club or club, is an entertainment venue and bar that usually operates late into the night. A nightclub is generally distinguished from regular. The Tower of Power halftime show closes with the funky Down to the Nightclub before the rockin' reprise of What Is Hip? The steady buildup leads to the finale.