Personnel one has included in Solicitor at Law’s contract (7)
I believe the answer is:
shrivel
'contract' is the definition.
(thesaurus)
'personnel one has included in solicitor at law's' is the wordplay.
'personnel' becomes 'hr' (Human Resources).
'one has' becomes 'ive' (contraction of I have).
'included in' is an insertion indicator.
'solicitor at law' becomes 'sl' (legal abbreviation).
'hr'+'ive'='hrive'
'hrive' placed inside 'sl' is 'SHRIVEL'.
(Other definitions for shrivel that I've seen before include "Dehydrate" , "Become dry and withered" , "Wither, shrink" , "Shrink as from cold" , "Become shrunken and wrinkled" .)