Guide words are used in reference books, such as dictionaries, phone books, encyclopedias, etc. At the top of the page, of the mentioned books, there are two words. These words ‘guide’ you so that you know what words will be found on that page. The guide word in the first column is the first word on the page, the guide word above the second column is the last word that will be on that page. All the words in between these 2 guide words will be on that page alphabetically.