reg·is·tra·tion 
(rĕj′ĭ-strāshən)
(rĕj′ĭ-strāshən)n.
1. The act of registering: voter registration.
2. The number of persons registered; enrollment.
3. An entry in a register.
4. A document certifying an act of registering.
5. Music
a. A combination of organ stops selected to be used in playing a piece.
b. The technique of selecting and adjusting organ stops.