A tray for making cubes of ice in a refrigerator WordNet 3.0 & Open English WordNet

A household item usually in the form of a plastic or metal device with a series of indentations such that the item may be easily filled with water (or another liquid) for the purpose of being placed in a freezer, from which it will later be removed, at which point it will contain easily separable ice cubes (or frozen cubes of whatever liquid was placed in it). Wiktionary

Tray. Wiktionary (translation)