Very stupid (7)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
idiotic
'very stupid' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for idiotic that I've seen before include "Witless" , "half-baked" , "Half witted" , "Inviting ridicule" , "Stupid, foolish" .)