Wiktionary
undercard
n. 1 A list of minor or supporting contests printed on the same bill as the main event (primarily fighting or racing, such as the main fight at a boxing match or wrestling, horse or car racing, etc.), occurring before or after the main event. 2 The events so listed. 3 (context poker English) A card lower than another given card or pair.
Wikipedia
Undercard (album)
Undercard is an album by indie-rock band The Extra Lens, which features members of The Mountain Goats and Nothing Painted Blue. The album was released on October 19, 2010.
Usage examples of "undercard".
This, the Guard lieutenant colonel knew, would be the reconnaissance battle, the undercard for the main event, with the lightweights duking it out before the heavyweights closed.