One who'll succeed in Scottish town, we hear (4)
I believe the answer is:
heir
'one who'll succeed' is the definition.
(an heir is someone's successor)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for heir that I've seen before include "One who will succeed to title" , "Successor to position or estate" , "one's to inherit throne!" , "Beneficiary, inheritor" , "Natural successor" .)