1. A word translation device that performs word translation among a plurality of languages, comprising: a storage unit that stores at least a first word search structure, a second word search structure, a first word and translation information record, and a second word information and translation record in a dictionary, the first word search structure being provided for searching for a word of a first language, the second word search structure being provided for searching for a word of a second language, the first word and translation information record including word-associated information and translation information as to words stored in the first word search structure, the second word and translation information record including word-associated information and translation information as to words stored in the second word search structure.