Green’s Dictionary of Slang

bullet n.1

1. [late 16C; 19C] in pl., the testicles.

2. [mid-19C+] a notice of dismissal; usu. in phrs. below.

3. [1960s–70s] (US) an ejaculation of semen.

In phrases

cop the bullet (v.)

[mid-19C+] to be dismissed from a job.

get the bullet (v.)

[mid-19C+] to be thrown out of a place or dismissed from one’s employment; to lose a relationship.

give someone the bullet (v.)

1. [late 19C+] to dismiss from employment, to throw out of a place.

2. [1930s+] to jilt, to terminate a relationship with.

shake the bullet at (v.)

[mid-19C] to threaten with dismissal, but not actually to dismiss.

shoot bullets (v.)

[1970s+] (US gay) to ejaculate (into a mouth or anus).