老衰

• Reading: ろうすい
• Romaji: rousui
• Kanji breakdown: 老 (rou) — old age, aging; 衰 (sui) — decline, weaken, wane
• Pronunciation: /ɾoː.sɯi/

Meaning

Senility; infirmity due to old age; natural decline in old age. The gradual weakening of bodily functions that occurs with advanced age.

A noun and suru-verb (老衰する) used in medical and everyday contexts to describe age-related physical and cognitive decline. 老衰死 (death from natural old age) is the official cause of death on death certificates when no specific disease is identified. As Japan's population ages rapidly, 老衰 has become an increasingly common cause of death and a focus of geriatric medicine and end-of-life care policy.

Examples

1. 祖母は98歳で老衰により安らかに息を引き取った。 My grandmother passed away peacefully at the age of 98 from natural causes due to old age.
2. 現代では老衰死を迎えるまで健康でいられる人が増えている。 In modern times, more and more people are able to stay healthy until they die of old age.
3. 老衰による身体機能の低下は、個人差が大きく一概には言えない。 The decline in bodily functions due to aging varies greatly from person to person and cannot be generalized.

Usage Guide

Context: medicine, elderly care, end-of-life, aging, geriatrics

Tone: solemn, matter-of-fact

Origin & History

Sino-Japanese compound: 老 (rou) means old age or aging, and 衰 (sui) means decline, weakening, or waning. Together they describe the natural waning of vitality with advancing age. Used in Chinese classical texts and central to discussions of natural death in Japanese culture.

Cultural Context

Era: Classical-Modern

Generation: Adult

Social background: Universal