com·bi·na·tion 
(kŏm′bə-nāshən)
(kŏm′bə-nāshən)n.
1. The act of combining or the state of being combined.
2. The result of combining.
3. An alliance of persons or parties for a common purpose; an association.
4. A sequence of numbers or letters used to open a combination lock.
5. Mathematics One or more elements selected from a set without regard to the order of selection.
com′bi·nation·al adj.