Slang is formed from a combination of street language and involves the informal or non-standard use of words. Slang words are often associated with younger groups but can also be used informally between close friends or coworkers. Some examples of slang terms provided are "airhead" meaning a foolish person, and "bird" or "chick" which were formerly used to refer to women but are now considered offensive. Slang terms can also refer to money, such as using "buck" to refer to an American dollar. Specific communities may also have their own specialized slang that is only understood within that group. Slang terms are also sometimes derived from natural speech patterns and contractions like "cuppa" meaning "cup