性命
xìng mìng · HSK 7
life
性命 = 性 nature + 命 fate/life = one's living existence
命 alone is life/fate; pairing it with 性 (one's inborn nature) yields 性命, the physical life a creature actually has. Often used when life is at stake, as in 性命攸关 (a matter of life and death).
性 — heart radical 忄 + 生 (life/birth)
性 is a semantic-phonetic compound. The heart radical 忄 supplies the meaning, pointing to inner feelings or innate qualities, while 生 ('birth, life') gives the sound and hints at what one is born with. It originally meant 'inborn nature' and later extended to 'character,' 'gender,' and 'sex.'
命 — 亼 (gather) + 卩 (kneeling person) + 口 (mouth)
Originally depicted a kneeling figure receiving an oral command from above, combining 令 (order) with an added 口 (mouth) for emphasis. The image of authority issuing decrees extended from 'command' to 'mandate' and then 'destiny, life,' as one's fate was seen as decreed by Heaven.