What does “sablier” mean in French?

Le sable is sand. Add -ier and you get un sablier: the object that holds it, an hourglass. That ending is one of French’s most productive, and one of its most useful jobs is turning the name of a content into the name of its container. Once you notice it, un sucrier, un saladier and un cendrier decode themselves — sugar bowl, salad bowl, ashtray.

The same suffix names the plant that yields a fruit: pomme → pommier, cerise → cerisier, poire → poirier. Container or tree, the logic is identical — -ier marks the thing that the first word comes out of, or goes into.