No participant in the betting, but one rakes it in (8)
I believe the answer is:
croupier
'no participant' is the definition.
The definition and answer can be both people as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
I don't understand the remainder of the clue.
(Other definitions for croupier that I've seen before include "Person in charge of gambling-table" , "Gaming table attendant" , "Roulette attendant" , "Leisure worker" , "I procure (anag.)" .)