You can use unsuspecting to describe someone who is not at all aware of something that is happening or going to happen.
例句
The co-defendants are charged with selling worthless junk bonds to thousands of unsuspecting depositors.此案的共同被告因向数千不明真相的存款人出售毫无价值的垃圾债券而被起诉。...his unsuspecting victim.他的不明真相的受害人
英汉词典释义
adj.
不怀疑的,无猜疑的,可信任的
Don’t be an unsuspecting elder.不要做一个轻信的年长者。Numerous pitfalls await unsuspecting investors.数不清的陷阱等待毫无戒心的投资者。I think she palmed off the stolen necklace on some unsuspecting old lady.我想她已经把偷来的项链脱了手给一位没有防备的老妇人。
英英词典释义
Adjective
1. not suspicious;
"deceiving the unsuspecting public"
2. (often followed by `of') not knowing or expecting; not thinking likely;
"an unsuspecting victim""unsuspecting (or unaware) of the fact that I would one day be their leader"