private detective
private investigator
detective agency
A: I suspect someone is spying on me.
A：我怀疑有人在监视我。
B: Maybe you should hire a gumshoe to find out the truth.
B：也许你应该雇一个私家侦探来查明真相。
1) 私家侦探
2) 侦探
1. 私家侦探
noun
1. a detective, especially a private investigator
Synonym: detective, investigator