Definition of planetarily in US English:

planetarily

adverb

rare
  • In the manner of a planet; as regards a planet or planets; from a planetary viewpoint.

Origin

Early 17th century; earliest use found in John Donne (1572–1631), poet and Church of England clergyman. From planetary + -ly.

Pronunciation

planetarily

/ˈplanɪt(ə)rɪli/