Available Definitions:
1) a. - Possible, or liable, but not certain, to occur; incidental; casual.
2) a. - Dependent on that which is undetermined or unknown; as, the success of his undertaking is contingent upon events which he can not control.
3) a. - Dependent for effect on something that may or may not occur; as, a contingent estate.
4) n. - An event which may or may not happen; that which is unforeseen, undetermined, or dependent on something future; a contingency.
5) n. - That which falls to one in a division or apportionment among a number; a suitable share; proportion; esp., a quota of troops.