1. mixture: an association of different things or factors, or the act of mixing them We were saved by a combination of skill and good luck.
2. combined set: two or more people or things that are combined to form a set The red shirt and navy vest make a striking color combination.
3. numbers that open lock: a series of numbers or letters needed to open a combination lock
4. boxing series of punches: in boxing, two or more punches quickly delivered one after the other
5. alliance: an association between people or groups established in order to accomplish something
6. mathematics arrangement of numbers in subsets: an arrangement of the numbers or symbols in a mathematical set into smaller subsets without regard to the order in which those numbers or symbols appear
7. mathematics subset: a subset containing a specific number of the elements of a particular set, selected without regard to the order in which they were chosen
8. chess sequence of moves involving multiple pieces: in chess, a series of tactical moves involving two or more pieces
9. chemistry formation of compound: the union of substances in the formation of a chemical compound