noun · A title used by certain historical Chinese rulers, such as Tang Gaozong.

唐高宗曾自号“天皇”，与武后并称二圣。

noun · One of the three legendary sovereigns (Sanhuang) in Chinese mythology.

天皇、地皇和人皇在中国神话中并称三皇。

noun · The monarch and head of state of Japan.

德仁天皇是日本目前的国家元首。