noun
Colloquial term for a yakuza member or someone connected to organized crime. Often carries a rough or streetwise nuance.
See also: ヤクザ
あの筋者はこの辺りを縄張りにしている。
That yakuza guy controls this area as his turf.
筋者同士の抗争が激しくなっているらしい。
It seems the conflict between gangsters is intensifying.
ヤクザ is the standard, neutral term for a member of a Japanese organized crime group. 筋者 is a more colloquial, insider or street-level term with a rougher nuance.
Compound of 筋 (すじ, 'lineage' or 'connection') and 者 (もの, 'person'), literally 'person of a certain line/connection', referring to someone involved in organized crime. The exact historical derivation is uncertain.