keeper

noun

1. a person or thing that keeps; specif.,
   1. a guard, as of prisoners or animals
   2. a guardian or protector
   3. Chiefly Brit. a curator
   4. a custodian; caretaker
   5. Brit. a gamekeeper
   6. any of several devices for keeping something in place, as a clasp
   7. something that keeps or lasts (well or poorly)
2. Informal something worth keeping, as a fish large enough for a fisherman to keep legally
3. ☆ Football a play in which the quarterback takes the ball from the center and runs with it