dubious
1、怀疑,无把握,拿不准=doubtful
I was rather dubious about the whole idea.
我对这整个想法都持怀疑态度。
2、可疑的,不可信的,靠不住的,不诚实的=suspicious
They indulged in some highly dubious business practices to abtain their current position.
他们采取了一些极为可疑的商业手段以取得在目前市场上的地位。
3、不确定的,不一定好的
They consider the plan to be of dubious benefit to most families.
他们认为这项计划对大多数家庭不一定有好处。