sharp as a tack

(as) sharp as a tack

Intelligent and a quick-thinker. Ted's as sharp as a tack, so he'll find a solution to this problem. Of course Ellen is our valedictorian—she's as sharp as a tack.
See also: sharp, tack
Farlex Dictionary of Idioms.

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
The American Heritage® Dictionary of Idioms by Christine Ammer.

(as) sharp as a ˈtack

(American English) intelligent with a quick and lively mind: My grandmother’s 85 but she’s still sharp as tack.
A tack is a kind of small nail or pin.
See also: sharp, tack
Farlex Partner Idioms Dictionary

sharp as a tack

Singularly keen or cutting; also, mentally acute. This simile has largely supplanted the earlier sharp as a razor, needle, vinegar, and thorn, the last dating from the fifteenth century and appearing in John Ray’s 1670 proverb collection. The current cliché dates from the late nineteenth or early twentieth century and appeared in a 1912 issue of Dialect Notes: “They won’t fool him; he’s sharp as tacks.”
See also: sharp, tack
The Dictionary of Clichés by Christine Ammer
See also:
  • (as) sharp as a tack
  • be as sharp as a tack
  • (as) sharp as a needle
  • sharp as a needle
  • (as) sharp as a whip
  • (as) sharp as a razor
  • razor
  • sharp as a razor
  • sharp
  • look sharp
References in periodicals archive
The 'Charlie And The Chocolate Factory' star told NBC's "Today" show that Heard is a wonderful girl, who is sharp as a tack, wonderful, Southern belle and sweet as can be and good for him, the New York Post reported.
Emily's pals might think she's losing her marbles tonight when she makes a generous offer to put Norris's mind at rest, but it's just further proof that she's still as sharp as a tack.
The Grand Old Man of football is now in his mideighties but still as sharp as a tack and has just brought out the second volume of his memoirs entitled To The End Of The Road.
Bryan Prunty looked as sharp as a tack but didn't score.
Ex-neighbour Fay Evans in Leigh-on-Sea, Essex, said: "She was as sharp as a tack right to the end."
Sharp as a tack, in a tone that varies from stiffly formal to sardonic and knowing, Jessica Peers writes a memoir of her years spent in a residential school for autis-youth.
Vanessa Middleton, 12 years old and sharp as a tack, saw Mrs.
'She was sprightly, obviously as sharp as a tack and very steady on her legs.
She's sharp as a tack and, like Margaret, mistress of the facial expression.
She's funny, sharp as a tack and the best interviewer around.
And she landed the odds with the minimum of fuss, showing a smart turn of foot under Kieren Fallon to beat Sharp As A Tack by two and a half lengths.
My mum's always been sharp as a tack, but he said she was getting confused about things, couldn't remember if she'd paid the gas bill or where the flour was in the kitchen cupboards.
Jack is just five, but obviously sharp as a tack, so when his disabled mother got into difficulties with her wheelchair young Jack coolly and calmly dialled 999 and waited for the arrival of the cavalry.