shyster

The etymology of 'shyster' is obscure and contested, though it is firmly an American English coinage from the mid-19th century. The most plausible theory links it to the German surname 'Scheisser', derived from the vulgar verb 'scheissen' (to defecate), used as a derogatory term for a contemptible person. Another theory suggests an origin from 'shy', implying someone not to be trusted, but this is considered folk etymology. Regardless of its precise source, the word emerged in the rough-and-tumble legal and political circles of New York City, crystallizing as a label for an unscrupulous, pettifogging practitioner of law or politics.

This word is considered unsegmentable into productive morphemes in modern English. It is a loanword whose origin is debated but not transparently analyzable into distinct meaning-bearing parts like 'shy' + 'ster'.