Related Clues:
- Sound in a long hallway
- It's said once but heard twice
- Mythical nymph
- Be a verbal rubber stamp
- Drop back
- Bounce off the wall, in a way
- She adored Narcissus
- Dolphin's navigation aide
- Do likewise
- Repeat verbatim
- Returning waves, of sorts
- Rever-berate
- Resonate
- Repeat performance
- You've heard this before