Shade's a bit circumspect, really (7)
I believe the answer is:
spectre
'shade's' is the definition.
('spectre' can be a synonym of 'shade')
'a bit circumspect really' is the wordplay.
'a bit' indicates a hidden word (the answer is formed by a bit of the clue).
'SPECTRE' is hidden in the letters of 'circumspect really'.
(Other definitions for spectre that I've seen before include "Ghost, phantom, apparition" , "spirit" , "Enemy organisation for James Bond; ghost" , "after-image?" , "'Phantom, shade (7)'" .)