Ice cube

An ice cube was a piece of ice (traditionally, but not always cube-shaped) used for keeping beverages cold.

Onboard, Jonathan Archer and Commander  were fond of iced tea and had it in a  with ice cubes. Occasionally, they also had just water with ice cubes. 

''In 2259 of the alternate reality, referred to 's cold fusion device as a "super ice cube". Later, he had a drink in the bar that had a spherical "ice cube" floating in it.''