夜光 やこう Meanings Noun, の-adjective nocturnal luminescence; noctilucence Kanji 夜 night. Read as ヤ. 光 light. Read as コウ. Words containing 夜光 夜光虫 (やこうちゅう) Noctiluca scintillans (luminescent species of dinoflagellate) 夜光雲 (やこううん) noctilucent clouds 夜光時計 (やこうどけい) luminous watch And 1 more. Jinuma: Japanese Dictionary · Word lists