Pay them off in compassion (7)
I believe the answer is:
empathy
'compassion' is the definition.
(thesaurus)
'pay them off' is the wordplay.
'off' indicates anagramming the letters.
'pay'+'them'='paythem'
'paythem' with letters rearranged gives 'EMPATHY'.
'in' acts as a link.
(Other definitions for empathy that I've seen before include "Pay them (anag.)" , "Ability to identify with another's feelings" , "Psychological identification" , "Ability to share another's feelings" , "Intuitive fellow-feeling" .)