The origin of 'wonk' is obscure, with several competing theories. One prominent suggestion is that it emerged as a reversal of the slang term 'know', implying an obsessive know-it-all. Another theory traces it to early 20th-century American college slang, possibly related to 'wonky' meaning shaky or unreliable, later shifting to denote someone preoccupied with technical minutiae. It gained its definitive modern meaning in the late 20th century within American political journalism to describe a person obsessively focused on policy details, distinguishing it from a general enthusiast or nerd by its specific association with governmental and political arcana.

The word 'wonk' is considered a simplex word in modern English. It does not have transparent, separable morphemes derived from classical languages. Its origin is uncertain but likely a 20th-century American English coinage.