| Clue | Source | Date |
|---|---|---|
| Make less dense (E, not I) | The Times Concise | 18 Oct 2023 |
| Make thinner, as air | New York Times | 23 Jun 2020 |
| Thin umpire in bit of sunshine | ||
| Thin out | Newsday | 18 May 2017 |
| Thin light falling over sport official | ||
| Thin light surrounding judge | ||
| Further refine for umpire consumed by school type | Irish Times Crosaire | 15 Apr 2015 |
| Make less dense | ||
| Thin out | ||
| Make more refined | ||
| Thin out | ||
| Become thinner, as air | ||
| Make less dense | ||
| Thin out | ||
| Thin out | ||
| Make more subtle | ||
| Lessen the density of | ||
| Thin out | ||
| Become thinned | ||
| Make less dense | ||
| Become thinned | ||
| Make less dense | ||
| Make more subtle | ||
| Refine further | ||
| Reduce the density of | ||
| Thin out | ||
| Make thin or porous | ||
| Refine | ||
| Become less dense | ||
| Attenuate | ||
| Make less dense. | ||
| Make purer. | ||
| Make thin or less dense. | ||
| Attenuate. | ||
| Become less dense. |