Few traditional studies of the history of the Japanese language have conducted diachronic analyses that take into account the syntactic characteristics of Sino-Japanese words. Moreover, researchers have focused on "changing usages" or "enduring usages" from the outset. As a result, relatively few studies have explicitly analyzed "ephemeral usages" or "disappeared usages," even when such phenomena were noticed.
This paper examines the Sino-Japanese word meiwaku (迷惑), describing its original usage while tracing changes in its syntax and the rise and fall of its usages from the medieval period onward. It also analyzes the correlation between these changes and examines the factors behind them from perspectives such as "interpersonal politeness," "(inter)subjectification," and "syntactic efficiency." Specifically, the paper makes the following points: 1. The word meiwaku originated as a Sino-Japanese borrowing from Chinese. In its early stages, it was predominantly used in verb-predicate sentences to describe the feelings of confusion or inconvenience experienced by a third party. However, starting from the medieval period, it also began to be used in adjective-predicate sentences. This new syntactic construction, which initially emerged as a non-standard usage, eventually gained traction in colloquial materials and continued to be used as a preface expression to convey interpersonal consideration. Factors facilitating its spread include the demand for preface expressions aligned with changes in social structures from the medieval period onward and shifts in linguistic consciousness.
2. Through repeated usage in adjective-predicate constructions, meiwaku acquired an evaluative meaning (subjectification). Furthermore, as a preface expression conveying consideration for others, it was frequently used in contexts where it indirectly criticized or rejected others' actions (intersubjectification). Over time, it came to embody the substantive meaning of "an action that causes trouble or inconvenience to others." In the late medieval period and beyond, the "meiwaku + suru construction" and the "meiwaku + functional verb construction" emerged, which could express the meaning of "causing inconvenience to others." Regarding functional convenience, the functional verb construction was more efficient in describing the directionality of actions and has continued to be used up to the present. In contrast, the suru construction, which was less efficient in indicating the directionality of actions, was ultimately not adopted as a new usage despite its initial creation.