Finding divorces surprisingly variable (9)
I believe the answer is:
discovery
'finding' is the definition.
(thesaurus)
'divorces surprisingly variable' is the wordplay.
'surprisingly' indicates an anagram (a surprising ordering of the letters).
'variable' becomes 'y' (algebra).
'divorces' is an anagram of 'discover'.
'discover'+'y'='DISCOVERY'
(Other definitions for discovery that I've seen before include "Find - Scott's ship" , "Sailing vessel" , "old ship" , "Something newly found" , "Space shuttle which launched the Hubble telescope" .)