icingEnglishOxford Dictionary of Englishicing /ˈʌɪsɪŋ / ▸ noun [mass noun] 1 a mixture of sugar with water, egg white, or butter, used as a coating for cakes or biscuits. 2 the formation of ice on an aircraft, ship, or other vehicle, or in an engine. – PHRASES the icing on the cake (North American English the frosting on the cake) an attractive but inessential addition or enhancement: more goals would have been the icing on the cake.