in French "grève" is an alternative name for beach. In Paris there was once a "place de grève" where boats could land easily. It was also a gathering point for people seeking employment - many people worked as day laborers in the days before the French revolution. The name of the place went through the French language to designate first the place, then the people who were gathering there not working, then the fact of not working. Nowadays "faire la grève" is to strike.