Abstract
This paper examines the usage of deaf-related vocabulary in medieval Japanese medical books, both diachronically and synchronically. The study focuses on three key books: Ishin’hō (compiled by a physician in Kyoto during the mid-Heian period), Ton’ishō (compiled by a priest-physician in Kamakura during the late Kamakura period), and Fukuden’hō (compiled by a priest-physician in Kyoto during the Nambokuchō period). By comparing these sources with medieval dictionaries, the study categorizes and analyzes their linguistic characteristics, contributing to the historical understanding of deaf words in Japan. The findings reveal that the terms mimi-shii, mimi-kikazu, and mimi-tsubure, which are associated with two kanji 聾 (rō) or 耳聾 (nirō/jirō), exhibit fluctuations between various opposing linguistic concepts, such as ‘standard translation vs. supplementary Japanese readings’ and ‘Kanbun-style readings vs. colloquial expressions’, depending on their historical context and the characteristics of the medical books in which they appear. Specifically, the mimi-shii family, which includes variations resulting from the Ha-line sound shift, appears sporadically in different editions of Ishin’hō, Ton’ishō, and Fukuden’hō. Additionally, instances of these terms being annotated alongside the mimi-kikazu and mimi-tsubure families were observed. The mimikikazu family also appears sporadically in Ishin’hō, Ton’ishō, and Fukuden’hō, but exhibits a mixed nature—some terms retain strong noun-like qualities, while others remain in their adverbial form. Meanwhile, the mimi-tsubure family is attested in various editions of Fukuden’hō, suggesting that its linguistic history may date back to the Nambokuchō period. Ultimately, this study demonstrates that the deaf words found in medieval Japanese medical books consists of three interrelated lexical systems—mimi-shii, mimi-kikazu, and mimitsubure—
which form a multilayered structure diachronically and a multifaceted structure
synchronically.
https://ror.org/04whwem28 
