Exclude a hard-hearted bighead (3)
I believe the answer is:
bar
'exclude' is the definition.
(I know that exclude can be written as bar)
'a hard-hearted bighead' is the wordplay.
I cannot quite understand how this works, but
'a' is within the answer.
'bighead' could be 'b' (the head letter of 'big') and 'b' is located in the answer.
A single letter 'r' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for bar that I've seen before include "In Mississippi, measure" , "sovereign" , "Ballet dancer's exercise rail" , "Hostelry" , "Prevent; sandbank" .)