Covered with ice
frozen over, iced, glaring, freezing, glacial, frostbound, glassy, sleeted, frosted, frosty, smooth as glass; see also slippery.
freezing, glacial, polar; see cold 1.
Another word for icy
Very cold: arctic, boreal, freezing, frigid, frosty, gelid, glacial, polar, wintry. (Archaic) frore. Idiom: bitter (or bitterly) cold. See hot
Lacking all friendliness and warmth: cold, frigid, frosty, glacial. See attitude, hot