1. Military term meaning "negative," "no," or "not." Used within NATO and Allied naval forces, including the United States.
2. Used in combination with the naval semaphoric signal and term Bravo Zulu (or BZ), meaning "well done" to indicate NEGAT BZ or "not well done".
Midshipman: Sir, what's your read on the report I submitted yesterday?
Captain: NEGAT Bravo Zulu, son. I suggest you clear your night and take another crack at it.