Collocations for stupid - adj.

appear, be, feel, look, seem, sound
I felt really stupid when I realized what had happened. | My sister made me look stupid in front of all my friends.

act
(informal) I decided it was best to act stupid.

bloody
(taboo),

damn/damned, exceptionally, extremely, fucking
(taboo),

incredibly, monumentally, particularly, really, very | absolutely, completely, (just) plain, utterly
That was just plain stupid!

not entirely
I''m not entirely stupid. I checked the train times before we came out.

a bit, a little, pretty, quite, rather | enough, sufficiently
He''s stupid enough to believe anything.

crassly, grossly
a crassly stupid thing to do