/ayt"bawl'/ , n.
1. Pool.
a. a black ball bearing the number eight.
b. a game in which one player or side must pocket all of either the solid-color balls or the striped ones before being permitted to attempt the pocketing of the eightball, which wins.
2. Slang. an inept person.
3. behind the eightball , Informal. in a difficult, disadvantageous, or uncomfortable situation: He hasn't studied all term, and now he's behind the eightball.
[ 1930-35, Amer.; EIGHT + BALL 1 ]