be (as) thick as two short planks

be (as) thick as two short planks

To be remarkably stupid, dimwitted, or obtuse. I was as thick as two short planks back in high school. Good thing I straightened out in college. Jen's new girlfriend is very nice, but she's thick as two short planks.
See also: plank, short, thick, two
Farlex Dictionary of Idioms.
See also:
  • (as) thick as two short planks
  • thick as two short planks
  • thick as two planks
  • (as) thick as two planks
  • be (as) thick as a short plank
  • be (as) thick as a brick