Clipping of Newfoundland.

(American football) Someone who plays in the NFL.

Initialism of no first use. (of nuclear weapons) / (set theory) Initialism of New Foundations with urelements.

Initialism of New Found Glory, an American pop punk band formed in 1997.

(US, slang) no fucking good (or, bowdlerized, no freaking good). This mark is written on an object to identify it as unusable, having failed inspection, and so on. Often seen in manufacturing environments and the U.S. military.

Initialism of no fixed abode. / (military) Initialism of non-forecast airlift. / Initialism of nondeterministic finite-state automaton.

(Philippines) Initialism of National Food Authority. / (Uganda) Initialism of National Forestry Authority.

(journalism) Initialism of not for attribution; indicating that a source must not be named.

(law enforcement, criminal law, UK, Malaysia) Initialism of no further action; a potential outcome for a suspect from a police investigation.

(law enforcement slang, UK) To formally end the police investigation of a suspect with no further action.