1. Home
2. Idioms
3. sharp as a tack

sharp as a tack

---

---

(as) sharp as a tack

very intelligent He may be old in years, but he's still as sharp as a tack and knows what he's talking about.

See also: sharp, tack

sharp as a tack

Also, sharp as a razor. Mentally acute. For example, She's very witty-she's sharp as a tack. These similes are also used literally to mean "having a keen cutting edge" and have largely replaced the earlier sharp as a needle or thorn. The first dates from about 1900, the variant from the mid-1800s.

See also: sharp, tack