contingent

adj. 1 (usu. Foll. By on, upon) conditional, dependent (on an uncertain event or circumstance). 2 a that may or may not occur. B fortuitous. n. 1 body (of troops, ships, etc.) Forming part of a larger group. 2 group of people sharing an interest, origin, etc. (the oxford contingent). [latin: related to *contact]

a. Possible, or liable, but not certain, to occur; incidental; casual.