In most cases, studies on the Zushoryō edition (圖書寮本 ) of Ruijū myōgi shō (類聚名義抄 ) has been centered on “source research”. They have been mainly about the exploration of the cited source manuscripts on the basis of which the editor’s intent and linguistic consciousness projected on them can be traced. The main target of such methodology is the definition of the Zushoryō edition of Ruijū myōgi shō because the source notes are clearly illustrated. However, it is difficult for the methodology to be applied to the entry because there are no clear clues such as source notes. Thus, if one needs to conduct his or her research on the entry, looking into source manuscripts only may not be sufficient. In order for such research to be worked out, it is necessary to find out the actual “relationship” between the definition(s) and the entry. I, in this research, focus primarily on the formality of the entry themselves. To start with, the entries under examination are confined to formal features with respect only to a plurality of letter proponents. And then, the entries are classified according to the criteria of the morphological feature and functional property, and simultaneously the amount and types of information are investigated. By means of examining how the entries and definitions respond to each other, I seek to clarify the substantial relationship between them. Resting upon such findings, I shall, in the final analysis, put forward an argument that there is a logical structure in Ruijū myōgi shō as a dictionary.