good omen; auspicious sign
A somewhat literary or formal term for a favorable omen, often associated with nature or celestial phenomena. Not an everyday word; more common in written or elevated contexts.
The old man said that an auspicious sign appeared among the clouds.
From 瑞 (auspicious, fresh) + 気 (spirit, atmosphere). The exact historical derivation is uncertain; the spelling is conventionally associated with favorable omens.