[transitive, intransitive] to have an idea that something is probably true or likely to happen, especially something bad, but without having definite proof suspect (something) If you suspect a gas leak, do not strike a match or even turn on an electric light. Suspecting nothing, he walked right into the trap. I didn’t want the neighbours suspecting anything. As I had suspected all along, he was not a real policeman. suspect (that)… I began to suspect (that) they were trying to get rid of me. I suspect (that) she might be lying. it is suspected that… It was suspected that the drugs had been brought into the country by boat. suspect somebody/something to be/have something She suspected him to be an impostor.