| Clue | Source | Date |
|---|---|---|
| A word that has no plural, e.g. knowledge or gold | ||
| Water or electricity, grammatically | Wall Street Journal | 06 Aug 2020 |
| Advice or knowledge, to grammarians | Newsday | 26 Mar 2016 |
| Service with unusually non-U china, say, or cutlery? | The Telegraph Toughie | 09 Jun 2015 |
| Word not usable with an indefinite article, such as "magic" or "dust" | LA Times Daily | 03 Jan 2015 |
| Word not usable with an indefinite article, such as "magic" or "dust" | ||
| Water or electricity, grammatically | ||
| "Grease," e.g. |