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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.

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RELATED WORDS

wise, shrewd, discriminating, sensitive, quick, sharp, astute, adroit, discerning, keen, canny, intelligent, crafty, insightful, vigorous, effective, deft, able, active, ready

Nearby words

  1. sharon,
  2. sharon fruit,
  3. sharon, ariel,
  4. sharonville,
  5. sharp,
  6. sharp practice,
  7. sharp, william,
  8. sharp-cut,
  9. sharp-eared,
  10. sharp-edged
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.