Trader in the French sea getting to sing (8)
I believe the answer is:
merchant
'trader' is the definition.
(thesaurus)
'french sea getting to sing' is the wordplay.
'french sea' becomes 'mer' ('sea' in French).
'getting to' means one lot of letters go next to another.
'sing' becomes 'chant' (chanting is a kind of singing).
'mer'+'chant'='MERCHANT'
'in the' is the link.
(Other definitions for merchant that I've seen before include "Shakespeare: ''The ... of Venice''" , "Broker" , "Dealer" , "Antonio, for one" , "Ten march (anag.)" .)