One might pick up Cockney's present? (3)
I believe the answer is:
ear
'pick up cockney's present?' is the definition.
The answer and definition can be both related to thinking as well as being singular nouns.
Maybe there's a link between them I don't understand?
'one might' is the wordplay.
I cannot really see how this works, but
'one' could be 'a' (a thing is one thing) and 'a' is present in the answer.
The remaining letters 'er' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for ear that I've seen before include "Aural organ" , "Seed container" , "Shell-like (slang)" , "Place for a plug" , "Lughole" .)