Learner's definition of POSSIBILITY
1 : a chance that something might exist, happen, or be true : the state or fact of being possible
[count] — usually + of
the possibility [=likelihood] of success/failure
He received a life sentence without the possibility of parole.
Is there a possibility of rain today?
Scientists are still unsure about the possibility of life on other planets.
It is not outside the range/realm of possibility that he could get laid off. [=he might get laid off]
(chiefly Brit) You shouldn't worry about things that are beyond the bounds of possibility. [=things that cannot happen]
2 [count] : something that might be done or might happen : something that is possible
Rain is a possibility today. [=it might rain today]
There is a wide range of possibilities [=options] to consider.
My first two ideas didn't work, but I thought of a third possibility.
We exhausted all/the possibilities. [=we did everything that we could think of doing]
The future holds untold possibilities.
His degree and job experience give him a wide range of possibilities for a career.
3 possibilities [plural] : abilities or qualities that could make someone or something better in the future : potential
a man of undetermined possibilities
The old house might not look like much now, but it has possibilities.