eightball

US: (āt′bôl′)

WordReference Random House Unabridged Dictionary of American English © 2025

eight•ball  (āt′bôl′), n. 

1. Games [Pool.]
   • a black ball bearing the number eight.
   • 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 Terms an inept person.
3. Idioms behind the eightball, [Informal.] in a difficult, disadvantageous, or uncomfortable situation:
   He hasn't studied all term, and now he's behind the eightball.

• eight + ball¹ 1930–35, American.