Contingent: A statement is contingent iff it is not necessarily true nor its denial necessarily false.
Thus, "London is the capital of France" is contingent and false; "Norway has more than a million inhabitants" contingent and true; "it rains or it does not rain" not contingent and necessarily true, and "it snows and it does not snow" not contingent and necessarily false.
Note there is a problem about contingent statements about the future, such as "it will rain tomorrow", since these are intuitively before tomorrow neither true nor false. Of course, the problem starts with the assumption that all statements are true or false. (See: Negation)
Also, one may truly claim that a statement is contingent, without claiming that is true or that it is false, e.g. because one does not know which it is. This is e.g. the case with many statements one can make about the past.