= 不良、チンピラ。
The exact etymology of hoodlum is unknown, but references to "hoodlums" roaming the streets of San Francisco first surfaced in the media in 1871. An article in the Cincinnati Commercial that year made reference to a young man who moved to the city to "escape the bullying of the San Francisco 'hoodlums.'"
Where Do 'Hoodlums' Come From? San Francisco : Code Switch : NPR
サンフランシスコの中国人が英語の語源になるのは他にも"shanghai"があるけれど、結構あるのかも。
