Anger consumes one beginning to sample spirits (7)
I believe the answer is:
'spirits' is the definition.
(wraith is a type of spirit or spectre)
'anger consumes one beginning to sample' is the wordplay.
'anger' becomes 'wrath' (wrath is a kind of anger).
'consumes' means one lot of letters goes inside another.
'one' becomes 'I' (Roman numeral).
'beginning to' indicates taking the first letters.
The initial letter of 'sample' is 's'.
'wrath' placed around 'i' is 'wraith'.
(Other definitions for wraiths that I've seen before include "Spectres" , "They haunt" , "spirits are made" .)