宇う宙ちゅう線せんうちゅうせんMeanings1nouncosmic rayScientific term for high-energy radiation from outer space. Used in physics and astronomy contexts.宇う宙ちゅう線せんは地ち球きゅうの大たい気きに絶たえず降ふり注そそいでいる。Cosmic rays are constantly raining down on the Earth's atmosphere.