Swine gets round in pub (4)
I believe the answer is:
boar
'swine' is the definition.
(male pig)
'round in pub' is the wordplay.
'round' becomes 'o' (round can mean a round object).
'in' means one lot of letters goes inside another.
'pub' becomes 'bar' (both are drinking establishments).
'o' placed into 'bar' is 'BOAR'.
'gets' is the link.
(Other definitions for boar that I've seen before include "Resting place for birds or bats" , "A wild male pig" , "Wild swine" , "Sow's mate" , "Uncastrated male hog" .)