A colloquialism is an expression not use in formal speech, writing or paralinguistics. Colloquialisms denote a manner of speaking or writing that is characteristic of familiar "common" conversation; informal colloquialisms can include words (such as "y'all" or "gonna" or "wanna"), phrases (such as "ain't nothin'", "dressed for bear" and "dead as a doornail"), or sometimes even an entire aphorism ("There's more than one way to skin a cat"). Dictionaries often display colloquial words and phrases with the abbreviation colloq. Colloquialisms are often used primarily within a limited geographical area. An example is for a soft drink. In the upper Midwest, it is commonly called "pop", while in other areas it's "soda." In the southern United States, it is commonly called "Coke". Another example of this would be the difference between Armour and Armor in the USA. While in the North-East it is common to see Armour, in other areas of the USA it is just Armor. ;)