noun: (uncountable, microbiology) Initialism of fluorescent speckle microscopy.
noun: (countable, computing) Initialism of finite-state machine. [(computing theory) A formalism for describing computation, consisting of a finite set of states and a transition function describing when to move from one state to another.]
noun: (uncountable, Internet slang, dating) Initialism of female seeking male.
noun: (telecommunications) Initialism of field strength meter.
noun: (UK, education) Initialism of free school meals.
noun: Initialism of Flying Spaghetti Monster. [(humorous) A deity consisting of spaghetti and meatballs, the creator of the universe according to the religion of Pastafarianism.]