Zero raised in cash (3)
I believe the answer is:
nil
'zero' is the definition.
(synonyms)
'raised in cash' is the wordplay.
'raised' is a reversal indicator (going up in a down clue).
'cash' becomes 'l' (The pound sterling symbol is an elaborate L).
'in' reversed gives 'ni'.
'ni'+'l'='NIL'
(Other definitions for nil that I've seen before include "none" , "You get nothing" , "Latin zero" , "Lacking value" , "Nothing, zilch" .)