fire·bomb (fīr′bŏm′) n. A bomb used to start a fire; an incendiary bomb. v. fire·bombed, fire·bomb·ing, fire·bombs v.tr. To attack (a target) with a firebomb. v.intr. To launch an attack against a target, using a firebomb. fire′bomb′er n. firebomb (ˈfaɪəˌbɒm) n (Firearms, Gunnery, Ordnance & Artillery) another name for incendiary 6. vb (tr) to attack with incendiary bombs. ˈfireˌbomber n. fire•bomb (ˈfaɪ ə rˌbɒm) n. 1. an explosive device with incendiary effects. v.t. 2.