Try for a prize though not quite complete (7)
I believe the answer is:
compete
'try' is the definition.
(thesaurus)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for compete that I've seen before include "Take part in contest" , "Contend (for a prize)" , "Take part in hope of winning" , "Take part (in race)" , "Struggle for victory" .)