If you are suspicious of someone or something, you do not trust them, and are careful when dealing with them.
He was rightly suspicious of meeting me until I reassured him I was not writing about him.
他对于我们的会面疑虑重重,直到我再次向他保证我写的东西与他无关。
If you are suspicious of someone or something, you believe that they are probably involved in a crime or some dishonest activity.
Two officers on patrol became suspicious of two men in a car.
两位巡警对一辆小汽车内的两名男子起了疑心。
If you describe someone or something as suspicious, you mean that there is some aspect of them which makes you think that they are involved in a crime or a dishonest activity.
He reported that two suspicious-looking characters had approached Callendar.
他报告说两名看似可疑的人曾接近过卡兰德。