| Clue | Source | Date |
|---|---|---|
| Exploring caverns | ||
| Speleology | ||
| Beginning to collapse | ||
| Giving in | Universal | 25 Oct 2022 |
| Exploring underground spaces | Irish Times Simplex | 10 Apr 2017 |
| Giving in to urge after losing initial resolve | ||
| Collapsing, with "in" | ||
| Collapsing, with "in" | ||
| ___ in (collapsing) |