what is the French word for market towns?

There isn't one specific French word for "market towns" in the sense of a town whose primary function is to host a market. However, you can use several options depending on the context and nuance you want to convey:

General terms:

* Villes (cities) - This is the most general term, but it can refer to any town, big or small.

* Bourgs (towns) - This is a more specific term for a town that is smaller than a city.

* Communes (municipalities) - This is a legal term that refers to any administrative unit in France, including towns and villages.

More specific terms:

* Villes de marché (market towns) - This is a literal translation of "market towns", but it's not commonly used.

* Bourgs marchands (merchant towns) - This term emphasizes the commercial aspect of the town.

* Villes commerçantes (commercial towns) - This term is broader than "market towns" and refers to any town with a strong commercial sector.

Descriptive phrases:

* Une ville qui a un marché important (a town that has an important market)

* Un bourg où il y a un marché (a town where there is a market)

* Une commune connue pour son marché (a municipality known for its market)

The best choice will depend on the specific context and the level of formality you desire.