A backer with spirit? (5)
I believe the answer is:
angel
This clue is a double definition.
'a backer' is the first definition.
('angel' can be a synonym of 'backer')
'spirit?' is the second definition.
'with' acts as a link.
(Other definitions for angel that I've seen before include "Theatre backer" , "Theatre financier" , "Very helpful person" , "Seraph or cherub?" , "backer for rep" .)