Asinine, silly (7)
I believe the answer is:
foolish
I believe this clue is a double definition.
'asinine' is the first definition.
(similar in meaning)
'silly' is the second definition.
(I know that silly can be written as foolish)
(Other definitions for foolish that I've seen before include "Silly, unwise" , "Imprudent" , "Absurd, not sensible" , "Unwise or ridiculous" , "Idiotic" .)