The answer is MOT, three letters. It is the French word for word, pulled into English inside the phrase bon mot, a good word, meaning a neat remark. Almost nobody says it aloud, yet it appears in grids constantly because three letters around a single vowel are hard to fill any other way.
How bon mot is actually used
A bon mot is a compliment paid to a sentence. It describes a remark that is short, finished and slightly pleased with itself, the sort of line that closes a subject rather than continuing it. A joke invites a laugh and then more jokes. A bon mot invites a pause.
English keeps the French plural in writing, bons mots, which is one of the few places an English writer is expected to pluralise both halves of a borrowed phrase. The register is worth knowing too. Calling something a bon mot is mildly arch, and it is a phrase used by people writing about conversation rather than by people having one. That is why it survives mainly in print, in memoirs, book reviews and appreciations, which happens to be exactly the register a crossword editor is comfortable quoting.
The other French phrases English kept for the same job
French supplied English with a set of ready made labels for talk, and they survive because English has no single word doing the same work. Le mot juste names the exactly right word, the one that makes a sentence land. A riposte is a return hit in fencing before it is a reply in an argument. Repartee names the whole skill of quick exchange rather than any one line of it.
Esprit de corps, sang froid and savoir faire follow the same pattern: a compact French label for something English can only reach through a clause. Borrowings survive where the borrowing saves words, and that is a better predictor of which ones stick than fashion is.
Why French loans crowd the short slots
Two things make them useful to a constructor. The first is arithmetic. A grid needs a steady supply of three and four letter entries built from common letters, and English runs thin there fast, while French loans arrive already vowel heavy: MOT, ELAN, ETUI, AMIE, ADIEU, ESPRIT.
The second is that they are unambiguous. A word nobody uses casually carries only one meaning, so it can be clued precisely, and a solver who learns it once never has to relearn it. That is why the same small handful recur across decades of puzzles. They are not there because editors are fond of French. They are there because nothing English will fit.
Sorting the rest of the field
The definition covers a crowd, so the enumeration does most of the sorting.
| Letters | Answer | What it implies |
|---|---|---|
| 3 | MOT | French loan, the crossword default |
| 3 | GAG | A joke told, not a remark made |
| 4 | QUIP | The plain English equivalent |
| 4 | JEST | Playful, not necessarily clever |
| 4 | BARB | Clever and aimed at somebody |
| 5 | SALLY | A sudden sortie in talk, older register |
| 6 | ZINGER | Informal, American, with a sting |
| 6 | RETORT | An answer given back |
| 7 | RIPOSTE | A reply rather than an opening |
| 7 | EPIGRAM | Polished and written down |
The adjective in the clue is what separates them. Cutting, barbed or pointed wants BARB. Playful or light wants JEST. A clue naming a reply, an answer or a comeback is describing a position in a conversation rather than a quality, which sends you to RIPOSTE or RETORT. A clue that mentions the page instead of the room, something published or inscribed, is reaching for EPIGRAM.
