Star Trek: 10 Secrets Of The USS Defiant You Need To Know
2. Warhead
The prominent nose section of the USS Defiant is one of the ship's most distinctive features, but was actually inherited from the aforementioned unused design for a Maquis fighter that the ship was based on. On that design, the nose section was a cockpit, but was made into a deflector dish housing when it was reworked into a Starfleet vessel.
According to Rick Sternbach and Michael Okuda's Star Trek: Deep Space Nine Technical Manual, this nose section wasn't just the deflector dish but was in fact a detachable warhead. According to the tech manual, the nose warhead was a last-ditch weapon in the Defiant's considerable arsenal, capable of separating from the primary hull of the ship and ramming an enemy vessel with its own impulse engine.
This tactic was never seen or even referenced on screen so its not technically canon. Ultimately, the most the nose of the Defiant did on the show was dock with space station Deep Space 9 (using an airlock that wasn't actually even present on the studio model), but the maneuver was used in the Pocket Books DS9 relaunch novel "Avatar".