smart as a whip

1. Very intelligent or clever, as in Little Brian is smart as a whip; he's only three and already learning to read. This simile alludes to the sharp crack of a whip. [Mid-1900s] Also see mind like a steel trap.

Related Words

• able 
• active 
• deft 
• effective 
• keen 
• ready 
• sharp 
• vigorous 
• wise