(as) thick as two short planks

Remarkably stupid, dimwitted, or obtuse. I smoked a lot of marijuana when I was in high school, so I turned out thick as two short planks by the time I finally graduated. Jen's new girlfriend is very nice, but she's as thick as two short planks.

Common Names:

Name	Pronounced	Usage
Bieito	bee-AY-taw	Galician
Janneke	YAHN-nə-kə	Dutch
Dilip	-	Indian, Hindi, Marathi, Gujarati, Bengali, Kannada, Tamil, Telugu, Malayalam
Golzar	-	Persian
Hulderic	-	Ancient Germanic
Malin	MAH-lin (Swedish, Norwegian), MAH-leen (Finnish)	Swedish, Norwegian, Finnish