Suspense is a feeling of excited waiting. If you have been waiting for weeks to get an answer to your proposal of marriage, you are being kept in suspense.
The verb form, suspend, literally means to keep hanging. Suspense can be used in all sorts of ways. Movies that keep you on the edge of your seat in fear use suspense to draw you in. Suspense doesn’t always have to be scary, but it is usually agitating. If you are in suspense, you’re waiting on something that you really have to know.