For cake decorating, icing and frosting describe the same thing: a sweet, often creamy coating spread over cakes and baked goods. The one place they clearly differ is outside the kitchen, since icing also names an infraction in ice hockey, where a player shoots the puck the length of the rink past the opponent's goal line untouched.
The core difference
Both words describe the sweet coating on a cake, but icing carries an extra, unrelated meaning in ice hockey that frosting does not share.
- icing — a sweet coating of sugar, and often butter or egg white, piped or spread onto cakes: she piped pink icing around the edge of the birthday cake.
- frosting — a sweet, often creamy coating spread over cakes and baked goods: the birthday cake had thick chocolate frosting.
How to tell them apart
There is no reliable rule for choosing between the two in a recipe, since both name the same finished layer on a cake, from a thin glossy glaze to a thick creamy layer. The memory hook is the sport, not the kitchen: icing in ice hockey is a specific infraction, called when the puck slides untouched past the far goal line, and that sense has nothing to do with baking.
The words come from similar roots, with icing built from “ice” plus “-ing” and frosting built from “frost” plus “-ing”, both describing a coating that resembles a layer of ice or frost on the cake's surface.
