(Canada) Initialism of Newfoundland and Labrador, a Canadian province. / (US, pharmacology) Initialism of National Formulary, a book of public pharmacopeial standards.

(slang) Initialism of not frat, denoting things counter to the culture of Greek life, particularly in the Southern United States

(US, aviation) Prefix code for NASA research fighter plane designations. / (pathology) Initialism of necrotizing fasciitis. / (pathology) Initialism of neurofibromatosis.

(computing) Initialism of Network File System. / (video games) Initialism of Need for Speed.

Initialism of not for sale.

(American football) Initialism of National Football League.

(mathematics) Initialism of no free lunch: applied to various restricting theorems.

(US) Acronym of National Foundation for Infectious Diseases.

(American football) Initialism of Non-football injury; any injury sustained by a player outside of games or training.

(Internet) Initialism of No fucking (freaking) idea; Expresses lack of knowledge on the subject matter / Initialism of no further information. Expresses lack of knowledge on the subject matter