Where does “jakuza” come from?

jakuza (Polish) comes from English yakuza, from Japanese やくざ, from Japanese 九, from Old Japanese 九.

Ancestry of “jakuza”, step by step

StepLanguageWordMeaning
1EnglishyakuzaA Japanese organized crime gang; A member of a...
2Japaneseやくざsomething that is worthless or useless; yakuza:...
3Japanese九nine; ninth; the ninth
4Old Japanese九—
Every word from Old Japanese 九 →Every word from Japanese 九 →Every word from Japanese やくざ →