Look: a ghost about to vanish (6)
I believe the answer is:
aspect
'look' is the definition.
(I know that look can be written as aspect)
'a ghost about to vanish' is the wordplay.
I cannot really see how this works, but
'a' is found in the answer.
'about' could be 'c' (circa) and 'c' is present in the answer.
The remaining letters 'spet' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
(Other definitions for aspect that I've seen before include "'View, perspective (6)'" , "Prospect, view" , "Distant view of a wide area" , "Prospect, facet" , "Scene, look" .)