光年 こうねん Meanings Noun light-year Kanji 光 light. Read as コウ. 年 year. Read as ネン. Example sentences 銀河系の大きさは、横断するのに少なくとも千光年か百万光年かかるだろう。The size of a galaxy may be as little as a thousand light-years across or as much as a million light-years across. Word lists Astronomy Jinuma: Japanese Dictionary · Word lists