Possible (9)
I believe the answer is:
potential
'possible' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for potential that I've seen before include "Capacity to become something" , "Possible (capacities of a person or situation)" , "Likely, though not yet tested" , "Capacity, ability to be developed" , "Latent abilities that may be developed" .)