Clever and almost completely correct (6)
I believe the answer is:
bright
'clever' is the definition.
(bright can mean clever or gifted)
'almost completely correct' is the wordplay.
'almost completely' becomes 'b' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'correct' becomes 'right' (right can mean correct).
'b'+'right'='BRIGHT'
'and' acts as a link.
Can you help me to learn more?
(Other definitions for bright that I've seen before include "Radiant or intelligent" , "Shining; intelligent" , "Clever - shining - sunny" , "Intelligent; well-lit" , "Blinding - intelligent" .)