C2 adjective /ˌhɑːrdˈbɪtn̩/
hard-bitten
頑固で経験豊富
Meaning
tough and experienced, not easily affected by emotions or hardship
Example
The hard-bitten detective showed no sign of surprise at the crime scene.
その経験豊富な探偵は犯罪現場で驚きの兆候を見せませんでした。