contingent
noun
°An event which may or may not happen; that which is unforeseen, undetermined, or dependent on something future; a contingency.
°That which falls to one in a division or apportionment among a number; a suitable share; proportion;.
adjective
°Possible or liable, but not certain to occur; incidental; casual.
°(with upon) Dependent on something that is undetermined or unknown.