(colloquial) To leave quickly / (idiomatic) To do (something, usually a written or verbal communication) quickly, and without hesitation or forethought.

present participle of shoot off

Third-person singular simple present indicative form of shoot off

(informal, idiomatic) To boast, or brag, or talk too much. / (informal, idiomatic) To disclose some information that was supposed to be secret.

Alternative form of shoot one's mouth off