(Originally among gay men) a person who prefers male sexual partners with large penises; (also more generally) a person who regards largeness as a desirable quality.
Origin
1960s; earliest use found in Lavender Lexicon.
Definition of size queen in US English:
size queen
noun
(Originally among gay men) a person who prefers male sexual partners with large penises; (also more generally) a person who regards largeness as a desirable quality.