Latin word possibilis comes from Latin posse, Latin -ibilis (-able; able or worthy to be (the recipient of an action).)
posse (Latin)
(post-Classical) force, body of men. (scholastic Latin) potentiality, capability of being. Power, ability "to be able (to)".
-ibilis (Latin)
-able; able or worthy to be (the recipient of an action).
possibilis (Latin)
Possible, that may exist, that may be done.