Spare one of the crowd (5)
I believe the answer is:
extra
This clue is a double definition.
'spare' is the first definition.
(I know that spare can be written as extra)
'one of the crowd' is the second definition.
(I've seen this before)
(Other definitions for extra that I've seen before include "Player taking little part" , "Additional expense" , "Another" , "Ancillary" , "Bonus; surplus" .)