North American Extremely clever or astute.
More example sentences
- As a lawyer in Southern California with a mind that's sharp as a tack, it's not good to miss even one day (she's mega-prolific) of her blog.
- It should be noted that his mind is sharp as a tack.
- She's a lovely 77-year-old woman, sharp as a tack, without an enemy in the world.
Definition of sharp as a tack in:
- The US English dictionary