I bet this is *[Colline][1]* (Hill) by Jean Giono (1929). To sum up:

- The story is set in a village of Provence, in southern France, called "Bastides Blanches". Giogo was born in Provence.
- An old man warns others against future strange phenomenons, and against nature taking revenge against humans.
- Characters start to freak out about it, and discuss a black cat who is seen everytime a catastrophe will happen (earthquakes, lighting striking people, etc.).
- Then, several bad events happen (water shortage in the village, people getting sick, a fire spreading to the village).
- There are several occurrences of the verb "déparler", in particular there's a scene where a dying character is described with this verb: 

> [...] il attend la mort en délirant à moitié. Des paroles
> mystérieuses, menaçantes, giclent de sa bouche édentée. **Il « déparle »**
> [...]

(I let non-French speakers use an automated translation tool, or refer to the official translation of the book, which unfortunately I don't have access to.)
- There's a "village idiot" called Gagou, who is the lover of Ulalie. Ulalie is depicted as a strong, independent woman.
- There was a [TV adaptation in 1980][2].


  [1]: https://en.wikipedia.org/wiki/Colline
  [2]: https://www.imdb.com/title/tt0368657/