(as) flat as a tack

(as) flat as a tack

Demoralized or unenergetic. She's been flat as a tack ever since she heard that she didn't get into her top choice school.
See also: flat, tack
Farlex Dictionary of Idioms.

flat as a tack

in very low spirits or lacking in energy. informal
The idea underlying the expression is of a tack that has been hammered in so that none of it protrudes.
See also: flat, tack
Farlex Partner Idioms Dictionary
See also:
  • flat as a tack
  • tack
  • able to do
  • able to do it
  • (as) flat as a strap
  • strap
  • be (as) flat as a pancake
  • in no time flat
  • in nothing flat
  • flatten out