Man maybe taking risks, losing races (5)
I believe the answer is:
being
'man maybe' is the definition.
'taking risks losing races' is the wordplay.
'taking risks' becomes 'betting'.
'losing' suggests deleting specific letters.
'races' becomes 'tt' (Isle of Man Tourist Trophy races).
'betting' with 'tt' taken away is 'BEING'.
(Other definitions for being that I've seen before include "Living thing" , "Person" , "A matter of 9 in the play" , "A living creature" , "See 9" .)