Hearty half of beer at the pub (5)
I believe the answer is:
inner
'hearty' is the definition.
Both the definition and answer are adjectives. Perhaps you can see an association between them that I don't see?
'half of beer at the pub' is the wordplay.
'half of' suggests halving the letters.
'at' means one lot of letters go next to another (I've seen this in other clues).
'the pub' becomes 'inn' (an inn is a type of pub).
'beer' with half the letters taken is 'er'.
'er' after 'inn' is 'INNER'.
Can you help me to learn more?
(Other definitions for inner that I've seen before include "Central area of a city, often old" , "Annulus nearest bull" , "(Hit on) part of target immediately next to the bullseye" , "Esoteric" , "More secret, private" .)