also: ぎょうせい
noun
Obsolete term for 'planet'; replaced by 惑星 in modern Japanese. Found only in historical or astronomical texts from the early modern period.
See also: 惑星
江戸時代の天文学書には「行星」という語が見られる。
The word 行星 can be found in Edo-period astronomy books.
Modern standard word for 'planet'; 行星 is its obsolete predecessor.
From Chinese 行星 (xíngxīng, 'planet'), literally 'moving star'. Adopted into Japanese with the on'yomi readings こうせい and ぎょうせい, but later replaced by 惑星.