contingent

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Liable to occur but not with certainty; possible: "All salaries are reckoned on contingent as well as on actual services” ( Ralph Waldo Emerson).
2. adj. Dependent on conditions or occurrences not yet established; conditional: arms sales contingent on the approval of Congress. See Synonyms at dependent.
3. adj. Happening by chance or accident; fortuitous. See Synonyms at accidental.
4. adj. Logic True only under certain conditions; not necessarily or universally true: a contingent proposition.
5. n. An event or condition that is likely but not inevitable.
6. n. A share or quota, as of troops, contributed to a general effort.
7. n. A representative group forming part of an assemblage.

Century Dictionary and Cyclopedia

1. Not existing or occurring through necessity; due to chance or to a free agent; accidentally existing or true; hence, without a known or apparent cause or reason, or caused by something which would not in every case act; dependent upon the will of a human being, or other finite free agent.
2. Dependent upon a foreseen possibility; provisionally liable to exist, happen, or take effect in the future; conditional: as, a contingent remainder after the payment of debts; a journey contingent upon the receipt of advices; a contingent promise.
3. n. An event dependent either upon accident or upon the will of a finite free agent; an event not determinable by any rule.
4. n. That which falls to one in a division or apportionment among a number; a quota; specifically, the share or proportion of troops to be furnished by one of several contracting powers; the share actually furnished: as, the Turkish contingent in the Crimean war.

Wiktionary

1. n. An event which may or may not happen; that which is unforeseen, undetermined, or dependent on something future; a contingency.
2. n. That which falls to one in a division or apportionment among a number; a suitable share; proportion;
3. n. military a quota of troops.
4. adj. Possible or liable, but not certain to occur; incidental; casual.
5. adj. Dependent on something that is undetermined or unknown.
6. adj. Dependent on something that may or may not occur.
7. adj. Not logically necessarily true or false.

GNU Webster's 1913

1. adj. Possible, or liable, but not certain, to occur; incidental; casual.
2. adj. Dependent on that which is undetermined or unknown.
3. adj. (Law) Dependent for effect on something that may or may not occur.
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.

WordNet 3.0

1. n. a gathering of persons representative of some larger group
2. adj. determined by conditions or circumstances that follow
3. adj. possible but not certain to occur
4. n. a temporary military unit
5. adj. uncertain because of uncontrollable circumstances