The icing on the cake – Idiom meaning

First, before we look at the meaning of this idiom, what is icing?
Icing = a sugary substance used as coating on cakes or cookies (biscuits) to make them look better or to enhance its flavour.

The meaning of Icing on the cake

Simple definition: Something that makes a good situation even better or a bad situation even worse.
The icing on the cake has two meanings and they strangely happen to be opposites.
This idiom can be used in a positive sense and a negative sense.
Positive meaning = an additional good thing happens to something that is already good or positive making that situation even better.
Negative meaning = an additional bad thing is added to another bad thing that has already happened making the situation worse. In this case the idiom is used in a sarcastic (or ironic) way.

Example Sentences using Icing on the cake

• Not only was I offered a higher salary, but the additional bonus I got was the icing on the cake.
• The athlete received a gold medal and the icing on the cake was that he also received a sponsorship deal.
• I got fired from my job, but the icing on the cake was when it started to rain while I was walking home.

The frosting on the cake

Another version of this idiom is “the frosting on the cake” which is used more in American English.