Kenneth G. Wilson (1923). The Columbia Guide to Standard American English. 1993.
fairy, faerie, faery, fay (adjs., nn.)
Fairy is the Standard word for the magical mythical being, both as noun and adjective. Also as noun it is the usually taboo and always disparaging slang term for a male homosexual; context must make clear which sense you intend. Faerie and faery are variant spellings of a poetic noun that means both fairyland and a fairy, again, the mythical creature; both can also be used as adjectives. Fay is also a literary word, meaning fairy or elf or, as an adjective, fairylike or elfin. See also FEY.