Wants to cut head's pay (8)
I believe the answer is:
earnings
'pay' is the definition.
(synonyms)
'wants to cut head's' is the wordplay.
'wants' becomes 'yearnings' (a yearning feeling is a feeling of want).
'to cut head' means to remove the first letter (I've seen 'cutting head' mean this).
'yearnings' with its initial letter taken away is 'EARNINGS'.
(Other definitions for earnings that I've seen before include "Salary" , "Grannie's (anag) -- income" , "Moneys received for grannies" , "Revenue" , "Money gained in work" .)