日本語借用形から探るアイヌ語sikerpe「キハダの実」の語源

要旨

There are three main types used for “Amur cork tree” among Japanese dialects: kihada-type, oobaku-type and siko-type. The first type is the form of Japanese origin for the tree. The second type is a loanword from Chinese黄蘗and it originally meant the yellow-colored inner bark of the tree used for medicine. The third type is a loanword from Ainu sikerpe “the fruit of the Amur cork tree” and it originally meant the fruit of the tree as it does in Ainu. This paper examines the siko-type in Japanese and reconstructs the Proto-Ainu form based on the reconstruction of the proto-loanword form in Japanese. The siko-type was likely borrowed into Old Japanese in western Japan, the political center of the time. Among the various forms in the siko-type, the one closest to the Ainu source is *sikorope reported in Akita Prefecture in northern Japan, which is reconstructed as the earliest loanword form. The proto-loanword form was later reinterpreted as a compound sikoro+pe, made of sikoro “the tree” and pe “the fruit.” In addition, the latter word pe changed to he through reanalysis of the phonological alternation of the historical root-initial *p > h. By removing pe or he “the fruit,” a new form sikoro emerged as a form for “the tree.” This new form is attested across wide area of Japan, covering Hokkaido in the north and Shiga Prefecture in the west. In Tohoku region, the r in sikoro+he changed to n, resulting in sikonohe. This form triggered a reinterpretation as siko no he “siko’s fruit,” in which no is understood as the genitive case marker in Japanese. As a result, siko newly emerged as the form representing the tree. In some cases, Japanese elements no ki “its tree” is added to give siko no ki for the purpose of emphasizing its semantic classification as a tree. This paper reconstructs the Proto-Ainu form for “the fruit of the Amur cork tree” as *siw kor pe, which means “the beholder of bitterness.” The reconstruction is based on its unique taste and the proto-loanword form *sikorope in Japanese. The Ainu form has changed to sikerpe through two sound changes: the deletion of w and the regressive assimilation of o to e. Old Japanese borrowed the Ainu form after it became *si kor pe by the deletion of w, and before it became *si ker pe by the regressive assimilation of o to e.

主題