Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
shyster (adj., n.)
The first syllable rhymes with dice. Both the noun (meaning “an unscrupulous lawyer”) and the adjective (meaning “characteristic of such cheats and their unethical methods”) are slang. The etymology is unclear: possibly the word comes from Scheuster, the name of a nineteenth-century lawyer with a bad reputation, or possibly from a figurative sense of the scatalogical German noun scheisser, “defecator.”
