Clever, but a bighead - yes? (6)
I believe the answer is:
bright
'clever' is the definition.
(bright can mean clever or gifted)
'a bighead yes?' is the wordplay.
I cannot quite see how this works, but
'bighead' could be 'b' (the head letter of 'big') and 'b' is found in the answer.
The remaining letters 'right' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'but' acts as a link.
Can you help me to learn more?
(Other definitions for bright that I've seen before include "supporter of free trade" , "Shining; intelligent" , "Clear" , "Jolly" , "Shiny" .)