FOOD RESOURCE COLLEGE OF HEALTH AND HUMAN SCIENCES, OREGON STATE UNIVERSITY
ICING
Garrett, Theodore Francis (edited by). 1898. the Encyclopedia of Practical Cookery. L. Upcott Gill, 170, Strand, W.C. London. Vol. II
it would seem as though this term is peculiar to British confectioners, as in all other European countries the name is associated with sugar, and in America is more frequently known as "frosting".
Grimes, William. 2004. Eating Your Worlds. Oxford University Press.
is a mixture of sugar with liquid or butter, typically flavored and colored, and used as a coating for cakes, pastries, or cookies.
