contingent

Short definition from Wiktionary

Noun

1. 1
   An event which may or may not happen; that which is unforeseen, undetermined, or dependent on something in the future.
2. 2
   That which falls to one in a division or apportionment among a number; a suitable share.
3. 3
   A quota of troops.

Adjective

1. 1
   Possible or liable, but not certain, to occur.
2. 2
   Dependent on something that is undetermined or unknown, that may or may not occur.
3. 3
   Not logically necessarily true or false.
4. 4
   Temporary.