Under-

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Across
  1. 1. A person who learns a role in case they need to replace another performer.
  2. 3. The lower surface of something.
  3. 4. To charge less money than the correct amount.
  4. 7. Dishonest or sneaky.
  5. 9. A passage beneath a road or railway.
  6. 10. Not active enough.
  7. 12. To fail to impress as much as expected.
  8. 13. Secretly working to gather information.
Down
  1. 2. A university student studying for their first degree.
  2. 5. Not old enough by law.
  3. 6. To think something is smaller, easier, or less important than it really is.
  4. 8. To weaken or damage gradually.
  5. 10. Clothing worn beneath outer clothes.
  6. 11. A first layer of paint.