Love break in hospital department (5)
I believe the answer is:
agape
'love' is the definition.
(thesaurus)
'break in hospital department' is the wordplay.
'break' becomes 'gap' ('gap' can be a synonym of 'break').
'in' means one lot of letters goes inside another.
'hospital department' becomes 'ae' (A&E, Accident & Emergency).
'gap' put inside 'ae' is 'AGAPE'.
(Other definitions for agape that I've seen before include "(Of mouth) wide open" , "Christian's love" , "ecclesiastical feast" , "love feast" , "showing disbelief" .)