Tomfool
/ˌtɑːmˈfuːl/
Definition 1 of 1
Pro Tip 1/3Archaic Usage
This term is old-fashioned and not commonly used. Understand it but prefer modern terms. 
You may find 'tomfool' in historical novels.
Pro Tip 2/3Colloquial Context
'Tomfool' is casual and might be seen as rude in formal situations. 
He jokingly called his friend a tomfool for wearing mismatched socks.
Pro Tip 3/3Emotional Connotation
Implies exasperation or playful criticism, not meant to deeply offend. 
Stop being a tomfool and concentrate on your work!