Trade in lead construction (4)
I believe the answer is:
deal
'trade in' is the definition.
(thesaurus)
'lead construction' is the wordplay.
'construction' is an anagram indicator (answer constructed from certain letters).
'lead' is an anagram of 'DEAL'.
(Other definitions for deal that I've seen before include "Softwood - business transaction" , "Treat" , "Loss of life" , "Bargain or kind of wood" , "Transact" .)