Other forms: ice cubes
The squarish chunk of ice that's floating in your cold drink is an ice cube. On a hot summer day, you might ask for extra ice cubes in your iced tea.
Ice cubes are small cube-shaped pieces of frozen water made in a freezer or an ice maker. You may keep a couple of ice cube trays full of ice in your freezer, while restaurants and cafes usually have large bins of frozen ice cubes. Ice cube trays were invented in the 1920s, originally made of rubber or metal, while today most trays are plastic. If someone orders a drink "on the rocks," it means "over ice."