Not the cleverest, anyhow (9)
I believe the answer is:
leastwise
'anyhow' is the definition.
(synonyms)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for leastwise that I've seen before include "in Hollywood at any rate" , "However (US)" , "in any case" , "anyway" , "If nothing else" .)