kill·file 
(kĭlfīl′)
(kĭlfīl′)n.
A file of character strings that are matched against incoming email or posts on electronic forums to eliminate items that one does not want to receive.
- ball boy
- ball buster
- ballbuster
- ball carrier
- ballcarrier
- ball cock
- ball control
- ballerina
- ballet
- balletic
- balletomane
- balletomania
- ballflower
- ball game
- ballgame
- ball girl
- ballista
- ballistic
- ballistically
- ballistician
- ballistic missile
- ballistics
- ballistocardiogram
- ballistocardiograph
- ballistocardiography