@duboi Can you please let us know what you are using for the Google search query when you are seeing the latin version of the meta description?
We reviewed the source code of the home page of your site and did find the latin text in the following section (see image here):
</aside></div><div class="column one-third"><aside id="text-3" class="widget widget_text"><h4>Rideaux, canapés, tapis à Caen</h4> <div class="textwidget"><p>Aenean luctus, neque ut interdum efficitur, magna enim porttitor tellus</p>
<p>Vitae finibus tortor turpis et tellus. Nullam pellentesque venenatis neque, in congue diam iaculis eget. Phasellus fermentum velit sed libero vitae finibus tortor. </p></div>
This appears to be part of some type of text widget. To make Google not show the latin text for any type of query we would recommend removing this text from the widget in question.