Colloquial

aphorism ("There's more than one way to skin a cat"). Colloquial words and phrases may be marked with the abbreviation "colloq." in dictionaries. Often colloquialisms are used within a certain geographical area.

In the past and in some quarters, overuse by native speakers of colloquialisms has been and is sometimes regarded as a sign of substandard ability with the language in question. But in the mouth of a non-native speaker, they are sometimes taken as signaling unusual facility with the language.

Compare: slang, jargon, variety (linguistics)