In the speculation I lost nothing (3)
I believe the answer is:
nil
'nothing' is the definition.
(eg nil is zero in football)
'in the speculation i lost' is the wordplay.
'in' indicates a hidden word.
'NIL' is hidden in the letters of 'speculation i lost'.
(Other definitions for nil that I've seen before include "Nothing, no value" , "Nothing, naught" , "duck" , "Don't despair - . . . desperandum" , "Nothing found in senility" .)