This document classifies and defines different types of words. It discusses words that are specific to a local region (localisms), used in casual conversation (colloquialisms), shortened forms (contractions), informal/non-standard (slang), abstract vs concrete, specific vs general, formal, synonymous, homonymous, general/vague (omnibus), technical/occupational (jargon), archaic, obsolete, overused (hackneyed), and antonyms. Examples are provided for many of the classifications. The purpose is to explain how words can be divided into different classes or categories.