noun, noun which may take the genitive case particle 'no'
urban villain; street hoodlum
A yojijukugo describing a rough, lawless person from the city streets; somewhat literary and not an everyday word.
彼は市井無頼の徒として知られていた。
He was known as a member of the urban ruffians.
その界隈は市井無頼のたまり場だった。
That neighborhood was a hangout for street hoodlums.
A yojijukugo composed of 市井 (town, streets) and 無頼 (lawless, villainous). The exact historical derivation is uncertain, but it follows a common pattern of combining two two-character compounds to form a set phrase.