Entry word is a term used to denote the first word in a dictionary or an index that is listed alphabetically. Some synonyms for the term "entry word" include guide word, keyword, headword, and main word. A guide word is a word at the top of a page that helps the reader locate a word in a dictionary. A keyword is a word used to identify a topic, concept or theme. Headword denotes the main word in a dictionary entry, and a main word is a word that represents the central meaning of a group of related words. Regardless of the term used, these words all serve to help organize and locate information in a dictionary or index.