able to be done or achieved, or able to exist:
I can't get it all done by Friday - it's just not possible.
Is it possible to buy tickets in advance?
They got as far as was humanly possible (= as far as anyone could have) before turning back.
that might or might not happen:
It's possible (that) Mira might turn up tonight.
"Do you think he'll end up in prison?" "It's very possible."
That's one possible solution to the problem.
that can be done or achieved, or that can exist:
[ + to infinitive ] Is it possible to get an earlier flight?
If possible I’d like to get there before noon.
We need to send that letter off as soon as possible.
that might or might not happen or exist:
[ + (that) clause ] It’s possible (that) Mary will turn up tonight.