14. The related-word registration device according to claim 1 , wherein the obtained search query in the search query obtaining code is stored in the search query storage in association with user identification information and acquisition time of the search query, the second search query specifying code causes at least one of said at least one processor to specify a second search query whose acquisition time is earlier than acquisition time of the first search query, from the extracted search queries, wherein the second search query specifying code causes at least one of said at least one processor to specify, as a second search query, a search query whose acquisition time is earlier than acquisition time of the first search query and having continuity based on the acquisition time in the extracted search queries.
14. The related-word registration device according to claim 1 , wherein the obtained search query in the search query obtaining code is stored in the search query storage in association with user identification information and acquisition time of the search query, the second search query specifying code causes at least one of said at least one processor to specify a second search query whose acquisition time is earlier than acquisition time of the first search query, from the extracted search queries, wherein the second search query specifying code causes at least one of said at least one processor to specify, as a second search query, a search query whose acquisition time is earlier than acquisition time of the first search query and having continuity based on the acquisition time in the extracted search queries. 15. The related-word registration device according to claim 14 , wherein the second search query specifying code causes at least one of said at least one processor to specify, as a second search query, a search query whose acquisition time is earlier than that of the first search query, having continuity based on the acquisition time, and whose number of search results is equal to or less than a predetermined value.