sharp as a tack

Idioms  

1. 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.

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Example Sentences

Whittle said Rutan had been courageous in his final hours at the hospital — sharp as a tack, calm and joking with them about what might come next after death.

From Seattle Times • May 4, 2024

“There is a difference because I know people that are 90 years old that are sharp as a tack — in fact, some of them are smarter than they were 20 years before.”

From Washington Times • Jul. 7, 2023

“There are huge individual differences in how people age. Some are sharp as a tack at 90 or 100, some have cognitive impairment in their 50’s,” Aldwin said.

From Slate • Feb. 18, 2023

"Passionate, erudite and sharp as a tack… her editorial ambition is second to none. We have been incredibly lucky to work alongside her."

From BBC • Aug. 26, 2022

Then all of a sudden old Spencer looked like he had something very good, something sharp as a tack, to say to me.

From "The Catcher in the Rye" by J. D. Salinger

Related Words

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