Slang and colloquial language. Slang, or extremely informal language is often confined to a relatively small group and usually becomes obsolete rather quickly, though some slang gains wide use (workaholic, duh). Colloquial language, such as a lot, in a bind, or snooze, is less informal, more widely used, and longer lasting than most slang.

Writers who use slang and colloquial language run the risk of not being understood or of not being taken seriously. If you are writing for a general audience about gun-control legislation, for example, and you use the term gat to refer to a weapon, some readers may not know what you mean, and others may be irritated by what they see as a frivolous reference to a deadly serious subject.