1. A server comprising: an input storage unit for storing input information containing location information indicating a geographical location, a word assigned to the location, and a user ID identifying a user having assigned the word to the location, the location information, the word, and the user ID being in association with one another; a determination unit for reading out first input information indicating locations to which a first word is assigned by a first user and second input information indicating locations to which a second word is assigned by a second user from the input storage unit, and determining whether the first and second users have assigned the words to a predetermined number or more of common locations based on the first and second input information; and a registration unit for creating dictionary data containing the first and second words in association with each other and entering the dictionary data into a dictionary storage unit when the determination unit determines that the first and second users have assigned the words to a predetermined number or more of common locations.