Definition of fireballs:
(n) :
A ball of fire, especially one associated with an explosion, or (fiction, mythology) thrown as a weapon.
(n) :
(figurative) (informal) A feisty, strong-willed person.
(n) :
(figurative) (baseball) Synonym of fastball (“a high-speed pitch of a baseball”).
(adj) :
(slang) Excellent, terrific.
(n) :
(astronomy) A meteor bright enough to cast shadows; a bolide.
(n) :
(astronautics) A bright glow caused by a spacecraft re-entering an atmosphere.