buttercream [buht-er kreem] noun
A type of frosting, typically used on cakes, although it can be used on cupcakes or as a filling for some cookies. It is often used incorrectly as a catch-all term for frosting, many times referring to frosting recipes that replace butter with vegetable shortening, which is about as far from butter in flavor and texture as you can get. True buttercream will contain butter, but the amount will vary from one frosting to another. For instance, confectioners’ sugar frostings have very little butter, while Italian meringue buttercream contains so much butter that it hardens when chilled.
Confectioners’ sugar-based frostings are very easy to make, but do not be deterred from trying something a bit more challenging like the Italian meringue. It is silky smooth rather than gritty, and is sophisticated and endlessly variable. Also see French, Swiss meringue and Italian meringue buttercream.