"Moon River" lyricist (6)
I believe the answer is:
mercer
'moon river lyricist' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for mercer that I've seen before include "Man of the cloth" , "Dealer in textile fabrics" , "Dealer in textiles or dry goods" , "Textile dealer (historical)" , "Supplier of fabrics" .)