Correct

钝

/ dùn / 
Strokes

Definition

blunt/stupid

Example

As an Adjective

blunt; dull

1
Dùndāo
钝刀

blunt/dull knife

As an Adjective

stupid; dull; slow-witted

2
Nǎozi
脑子
dùn
钝
de
得
hěn
很

have a slow mind; be slow-witted; have a thick head

3
Dùnshé
钝舌

be ineloquent