"cheese-like," late 14c., from cheese (n.1) + -y (2). Meaning "cheap, inferior" is attested from 1896, perhaps originally U.S. student slang, along with cheese (n.) "an ignorant, stupid person." In late 19c. British slang, cheesy was "fine, showy" (1858), probably from cheese (n.2) and some suggest the modern derogatory use is an "ironic reversal" of this. The word was in common use in medical writing in the late 19c. to describe morbid substances found in tubers, decaying flesh, etc.