A learning device includes a memory and a processor configured to execute a process including acquiring a plurality of documents, clustering the plurality of documents with respect to each of a first plurality of words, the first plurality of words being included in the plurality of documents, assigning a common label to a first word and a second word among the first plurality of words in a case where a cluster relating to the first word and a cluster relating to the second word resemble each other, and re-clustering, on the basis of the common label, the plurality of documents including the first word and the second word after the assigning the common label.