Meaning

1. key (to open doors)
2. key (of musical instrument)
3. key (in heraldry)
4. spanner, wrench
5. faucet, tap, water tap, spigot
6. curly bracket ({ and })
7. switch (a device to turn electric current on and off or direct its flow)
8. hold (position or grip used to control the opponent)
9. a game where a small metal disc is thrown at a small metal structure