Officers given hits feel unwell inside (8)
I believe the answer is:
bailiffs
'officers' is the definition.
(officers of the law)
'hits feel unwell inside' is the wordplay.
'hits' becomes 'biffs' (biffing is a kind of hitting).
'feel unwell' becomes 'ail' (I've seen this before).
'inside' means one lot of letters goes inside another.
'biffs' enclosing 'ail' is 'BAILIFFS'.
'given' is the link.
(Other definitions for bailiffs that I've seen before include "Sheriff's officers who execute writs" , "Strangely, FBI fails the court officers" , "Court officers who execute writs" , "Law officers who serve writs to confiscate goods" .)