I know that "bamboos are hollow and compartmentalized". "A bamboo rod has an empty middle". But I still cannot connect the dots! I can't think up any relation between bamboo + filch or swindling.
- Is this etymology related to that of 竹升?
https://www.wordsense.eu/%E7%AB%B9%E6%A7%93/
Noun 竹槓
- thick bamboo pole
- (figurative) rip-off
https://www.omgchinese.com/dictionary/chinese/%E7%AB%B9%E6%A7%93
COMMON WORDS WITH 竹槓
extortion by taking advantage of sb's weakness ( 敲竹杠 )