What does 過労死 Karoshi mean?

Karoshi is death caused by overwork. The word exists in law and in insurance claims, which distinguishes it from most vocabulary on this site: this is not a cultural concept but an administrative category.

The characters

過 (ka) means excess, going beyond. 労 (rou) is labor. 死 (shi) is death. Excess labor death, with no metaphor anywhere in it.

What it formally covers

Japanese law defines the term, and the workers' compensation system treats deaths of this kind as occupational, which gives the term legal weight rather than rhetorical weight. A related term covers suicide attributed to overwork, handled under the same machinery.

The mechanism usually described is cardiovascular: strokes and heart attacks following sustained periods of extreme hours, where the working pattern is judged to have been causal rather than incidental.

What a name makes possible

If a death is to be attributed to work, someone has to define the threshold, adjudicate the claim and record the outcome, and none of that is possible without a name.

English has no equivalent term, which is not evidence that the situation does not occur in English-speaking countries. It is evidence that those countries have not built the same administrative apparatus around it.

The framing to avoid

The word is often deployed abroad as a lurid detail about Japanese working culture, and it does describe something real about postwar working hours. It is also a term taken up by people trying to fix the problem: in 1988 lawyers set up the first karoshi hotlines.

Reading it as a symptom of national character misses that. A society that names a harm, recognizes it officially and pays compensation for it is a society arguing with itself about the harm, which is the opposite of accepting it.

Why it belongs on a site about anime vocabulary

Because it explains a stock character. The father who is never home, the exhausted office worker asleep on the last train, the manager who cannot refuse a demand: these are not lazy shorthand, they are drawn from the working conditions this word was coined to describe, and reading them as exaggeration misreads what the fiction is depicting.