Lady will account for resin (7)
I believe the answer is:
shellac
'resin' is the definition.
(thesaurus)
'lady will account' is the wordplay.
'lady' becomes 'she' (I've seen this in other clues).
'will' becomes 'll'.
'account' becomes 'ac'.
'she'+'ll'+'ac'='SHELLAC'
'for' is the link.
(Other definitions for shellac that I've seen before include "Varnish ingredient" , "Varnish derived from insect secretion" , "Resin from trees" , "Resin for varnishing" , "Resin used for varnish, formerly for records" .)