noun
the Sun, the Moon and the stars
Poetic term for the three celestial lights. Used in classical or literary contexts.
三光は天地を照らし続ける。
The three celestial lights continue to illuminate heaven and earth.
noun
three 20-point cards (hanafuda)
In hanafuda, a high-scoring meld consisting of three 20-point cards (the crane, the curtain, and the moon).
花札で三光を集めると高得点になる。
In hanafuda, collecting the three 20-point cards yields a high score.
From 三 (three) + 光 (light). The poetic sense refers to the three great celestial lights. The hanafuda sense is a specialized use of the same characters.