1. A glossary management device comprising: a read circuit that reads a document; a storage circuit that has a storage area for a glossary to which text segments extracted from the document that is read by the read circuit are to be added as entry terms; an acquisition circuit that acquires text data of the document; an analysis circuit that performs analysis of the text data acquired by the acquisition circuit to identify a language of the document and parts of speech of text segments in the text data and extracts one or more text segments from the document based on the analysis; a term matching circuit that performs matching for each of the extracted text segments against a public dictionary containing entry terms registered therein; and a registration circuit that adds to the glossary, each extracted text segment that does not match any entry term in the public dictionary, wherein the analysis circuit determines whether or not each extracted text segment is a proper noun, if the analysis circuit determines that the extracted text segment is not a proper noun, the term matching circuit performs matching of the extracted text segment against the public dictionary, and the registration circuit adds the extracted text segment to the glossary if the extracted text segment does not match any entry term in the public dictionary, and if the analysis circuit determines that the extracted text segment is a proper noun, the registration circuit adds the extracted text segment to the glossary without the term matching circuit performing matching of the extracted text segment against the public dictionary.