Bomber destroyer
Historically, several aircraft were designated bomber destroyers prior and during the Second World War. They were interceptor aircraft dedicated to destroy enemy bomber aircraft with exceptionally powerful armament. They were a generally intended for day use, so were a separate category from the existing night fighters.
The United States considered powerfully armed destroyers, like the Bell YFM-1 Airacuda prototype, to counter a potential attack of high-performance bombers. The Lockheed P-38 Lightning and Bell P-39 Airacobra were also designed with the aim of mounting very heavy armament, including 37 mm guns, in the anti-bomber role.
A deceptively similar, although completely different, designation was the German Zerstörer (meaning "destroyer"). Introduced on 1 May 1939, the term did specifically exclude the defensive anti-bomber role (leaving it for the light fighters), and envisaged a heavy fighter for offensive missions: escorting the bombers, long-range fighter suppression, and ground attack.