noun: (chiefly sports) Initialism of hall of fame. [(usually capitalized, often sports) A structure housing memorials to famous or illustrious individuals (especially ones of importance to some field), often containing a collection of memorabilia relating to them.]
noun: (chiefly sports) Initialism of hall-of-famer. [One who has achieved a spot in a hall of fame.]
noun: (functional programming) Initialism of higher-order function. [(computer science) A function that takes one or more functions as an input, and returns a function as a result.]