Slang

Slang consists of informal terms not recognized as proper usage or not found in older dictionaries, which express ideas or emotions of particular groups or cultures.

Slang is a product of culture, and changes over time. A review of the slang of the 1920s illustrates how much it does change.

Slang tends to exhibit more regional variation than standard English. For example, whereas an Englishman and a New Yorker can normally understand each other perfectly well, if either party uses a lot of slang, communication can become more of a problem.