The question seems a little odd, but it occurred to me:
There are a lot of historical references to French peasants - in medieval times, in pre-modern times, during the Revolution, etc. But nowadays you never hear anyone describing anyone in France as a peasant. Why? There are still a lot of rural farmers in France. Presumably some of them are still poor. Why are they not peasants?
I ask especially because it's not like the word 'peasant' has fallen entirely out of use. Go to any academic literature on development in poor countries and you'll find references to Nepali peasants, Cambodian peasants, Senegalese peasants, etc. But no French peasants.
So when did Western historians stop describing poor rural folks in France (and Western Europe generally) as peasants? Why? How has the meaning of the word changed over the years?
What makes a farmer a peasant? As with most questions of historical definitions, there's no universally accepted answer. Partially that's because being a "peasant" involves both economic and cultural factors. But the economic ones are central, and so we can say that in general a "peasant" is a preindustrial subsistence farmer.
That means it's someone who largely farms the land to provide food for them to eat, rather than running a cash crop operation. They also are preindustrial, which means they're farming using traditional methods of agriculture rather than mechanized equipment, industrial-scale fertilizer, etc.
There are exceptions to all of this, of course, and fuzzy boundaries. As one scholar noted, “Rural France is almost infinitely diverse, and almost any generalization about the peasantry becomes partially false as soon as it is formulated.” There were economic spectrums within "peasants," including some desperately poor, and some rather rich, with ample land and capital to spare. (A number of peasants were able to buy land seized from the Church during the Revolution, for example, considerably improving their livelihoods.) In some regions, the dominant crop wasn't grain or other food but grapes for wine; was a poor farmer not a "peasant" because his crop became wine for market, even if his standard of living was comparable to a peasant one department over who was growing grain to eat?
And there are complications: even "subsistence farmers" were heavily engaged with the market, sometimes selling their modest surpluses, or hiring themselves out as day labor periodically, or having their wives work at sewing or other crafts to sell. You also had "peasants" who didn't farm at all, but shared circumstances and a standard of living with farming peasants. Think of a poor clogmaker, for example, barely scraping by making his wooden shoes. He'd almost certainly still be considered a "peasant," because being a peasant was also partly a social class.
As to your specific question: France still had abundant "peasants" well through the 19th Century, but the numbers started to drastically decline in the second half of the century as increasing numbers of rural residents relocated to the cities. The ones who left were the ones with the most precarious economic lifestyle, often the ones with no land of their own, or only marginal land. The ones who remained were farming better land, or were able to buy up land vacated by their neighbors, and so their standard of living improved. Similarly, about this time, new plows and fertilizers and harvesting tools and other innovations began to become widespread, as did "scientific" approaches to agronomy, first with a handful of experimental farms, then to those large farmers with abundant capital, but eventually reaching the remaining smaller farmers.
Hopefully the answer for why the term "peasant" is used (not without controversy!) to describe some farmers in the developing world, but not in the developed world, should be obvious. While modern-day France, Britain, the United States, etc., do have farmers, they're not practicing subsistence agriculture and they're very much not relying on traditional, preindustrial practices, whereas some poorer countries arguably do still have farmers who fit that description.
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