Suffix for the well-to-do (4)
I believe the answer is:
aire
'suffix for the well-to-do' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for aire that I've seen before include "Northern English river, tributary of the Ouse" , "English flower" , "Major river of Yorkshire" , "River of the Yorkshire dales" , "flower of Yorkshire" .)