Perform a sort of scan (3)
I believe the answer is:
act
'perform' is the definition.
(acting is a kind of performing)
'a sort of scan' is the wordplay.
'sort of scan' becomes 'ct' (I can't explain this - if you can you should give a lot more credence to this answer).
'a'+'ct'='ACT'
Can you help me to learn more?
(Other definitions for act that I've seen before include "Bill successfully prosecuted" , "Exploit" , "Feign" , "turn" , "Assumed attitude" .)