"Lady Marmalade" singer LaBelle (5)
I believe the answer is:
patti
'lady marmalade singer labelle' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for patti that I've seen before include "Soprano" , "Italian singer" , "Adelina --, opera singer (1843-1919)" , "Adelina -, nineteenth to twentieth century sopr." .)