To be cranky means to be in a bad mood, to be upset, to be easily angered, to be grouchy. When you are cranky, you are having a bad day and things aren't going well for you, you are also probably tired. Don't be cranky with me. Don't be upset with me. Don't be grouchy. Don't be cross. (British say this more than Americans)

Cranky means annoyed/ in a bad mood/ angry. It's like maybe " don't get mad at me " or something like this. Hope I helped you out.