狂う

The core image of this verb is a deviation from a "correct," "normal," or "intended" state. Whether it refers to a person's mind, a mechanical device, or a structured plan, the essence is the loss of a standard or a breakdown of harmony.

When used regarding mental health, such as in the phrase "ki ga kuruu" (気が狂う), the expression is extremely strong and can be perceived as harsh or insensitive in modern Japanese. In professional or polite contexts, more clinical or indirect terms are preferred to avoid sounding derogatory.

In the context of machines or rhythms, it describes a loss of precision. For example, if a clock is "kurutte iru," it is not necessarily broken (stopped), but rather inaccurate. This nuance of "slight but critical misalignment" is key to distinguishing it from "kowareru" (to break).

When applied to plans or calculations, it suggests that an unexpected variable has disrupted the intended flow. It often carries a sense of frustration or helplessness, as the "gears" of the situation are no longer meshing correctly.