| Answer | Crossword Clue |
|---|---|
| HUM | Running sound |
| PURR | Smooth-running sound |
| PANT | Sound after running |
| PURR | Smooth-running engine sound |
| TOOTLE | Low running sound on a flute. |
| hoofbeat | the sound made by an animal's hoof in walking, running, etc. |
| purring | (of a vehicle or machine) Make such a sound when running smoothly at low speed |
| gurgling | Make a hollow bubbling sound like that made by water running out of a bottle |
