rattlebrain
/ˈrætəlˌbreɪn/
noun
- A silly, foolish, or scatterbrained person.
- Don't be such a rattlebrain — you left your keys in the fridge again.
- He's a lovable rattlebrain who can never remember where he parked.
- The old professor was a bit of a rattlebrain, always misplacing his glasses.
Synonyms