An example of a colloquialism is the cliche "Life's short."
Please avoid using any colloquialism or slang in any of your formal essays.
Using a colloquialism can be a good way to add some everyday language to a piece of creative writing.
Colloquialism: The machine has to learn how to recognize and translate colloquial phrases as well as idiomatic expressions such as C'est quoi, ça?
The privatized rail system has been such a disaster that Railtrack has become a colloquialism for a chaotic and crazy way to run things.
The Pelican has used an English colloquialism which has a similar meaning.