Subtle shade of meaning (6)
I believe the answer is:
nuance
'subtle shade of meaning' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for nuance that I've seen before include "Cue Ann into slight shade" , "Delicate shade of difference" , "Subtlety of meaning" , "Subtlety, nicety" , "Subtle shade of difference" .)