To suspect something means to believe it might be true without having solid proof yet. When you suspect your friend took the last cookie, you have a hunch based on clues (maybe crumbs on their shirt), but you don't know for certain. A detective might suspect a particular person committed a crime based on evidence, even while still investigating.

The feeling of suspecting often comes with uncertainty. You're not making wild guesses, you're drawing conclusions from what you observe, but you haven't confirmed them yet. A teacher might suspect students copied homework if their answers are strangely identical. You might suspect it's going to rain when you see dark clouds gathering, even before the first drops fall.

As a noun, a suspect is a person believed to have done something wrong, especially a crime. Police identify suspects based on evidence and witness statements, then investigate further to determine the truth. Being a suspect doesn't mean someone is guilty. It means investigators think they might be involved and need to gather more information.

The word carries a sense of doubt or mistrust. When you call someone or something suspicious, you mean it seems questionable or untrustworthy, like a suspicious excuse for missing homework or a suspicious character lurking around the neighborhood.