sharp as a tack
In real, traceable use. Part of the curated seed collection; community review is coming.
Meaning · English
Very intelligent.
Register: colloquial
Where it’s used:
Used
American English
Examples
When Mum died at ninety she was still as sharp as a tack. Everything else wore out.
Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30)
Sources & notes
Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30 via kaikki.org).
Common questions
What does “sharp as a tack” mean?
Very intelligent.
Is “sharp as a tack” formal or informal?
sharp as a tack is generally colloquial.