Idiom IQ: Can you guess the meaning behind these phrases?

Questions

1. What does the idiom “Break a leg” mean?
2. To “hit the nail on the head” means to do what?
3. The phrase “Piece of cake” means what?
4. What does “Bite the bullet” mean?
5. To “kick the bucket” is an idiom for what?
6. The expression “Let the cat out of the bag” means to do what?
7. “Under the weather” refers to feeling what?
8. “Spill the beans” means to do what?
9. The idiom “Burn the midnight oil” means to do what?
10. To “cost an arm and a leg” means something is what?

Answers

1. Good luck (or perform well)
2. To be exactly correct or accurate
3. Something easy
4. To endure a painful or difficult situation
5. To die
6. To reveal a secret
7. Feeling ill
8. To reveal a secret unintentionally
9. To work late into the night
10. Very expensive