1. The act of putting something in position
2. A group of things of the same kind that belong together and are so used:
3. An abstract collection of numbers or symbols
4. An unofficial association of people or groups; SYN. circle, band, lot.
5. Several exercises intended to be done in series; SYN. exercise set.
6. Any electronic equipment that receives or transmits radio or tv signals
7. A unit of play in tennis or squash
8. (Psychology) A temporary readiness to respond in a particular way; SYN. readiness.
9. The descent of a heavenly body below the horizon