| Clue | Source | Date |
|---|---|---|
| To a frightening extent | ||
| Unnervingly (7) | ||
| In an unnerving manner (7) | ||
| Carl is staggering by yard in an alarming way (7) | ||
| Frighteningly (7) | Puzzler | 10 Mar 2024 |
| Frighteningly (7) | Puzzler | 14 Dec 2023 |
| In an alarming way | ||
| In a frightening way | New York Times | 29 Jun 2015 |
| In a frightening way | ||
| In a spine-tingling manner | ||
| In an alarming way | ||
| In an alarming manner | ||
| In a frightful way | ||
| In blood-curdling style. |