A gambling game, a variety of the game of lotto, played with balls or knobs, numbered, and cards also numbered.
1971, Hunter S. Thompson, Fear and Loathing in Las Vegas (Harper Perennial 2005), page 41:
Memories of this night are extremely hazy. All I have, for guide-pegs, is a pocketful of keno cards and cocktail napkins, all covered with scribbled notes.