Planetary

How to spell planetary

9 letters · 4 syllables

How to pronounce planetary

Say the part in capitals loudest.

What does planetary mean?

1. adjectiveRelating to a planet or to the planets of a solar system.

Planetary in a sentence

• The documentary explored planetary formation around distant stars.

• Scientists study planetary orbits to predict the positions of the planets.

Where does planetary come from?

Language of origin: Greek

This word traces back to the Greek planetes, meaning 'wanderer', a name the ancient Greeks gave to the bright points of light that drifted against the fixed background of stars night after night. That noun passed into Late Latin as planeta and then sprouted the Latin adjective planetarius, meaning 'belonging to a planet'. English borrowed the adjective in the early 1600s, just as astronomers were beginning to map the solar system in earnest. The hidden charm in the spelling is that the wandering 'planet' sits whole and unchanged at the front; once you can spell planet, you only need to add the familiar '-ary' ending. The same -ary suffix attaches the idea of 'relating to' in dozens of English words such as 'stationary' and 'budgetary', which is a useful pattern to lean on.

How the word is built

• planet- (from Greek planetes: wanderer)
• -ary (suffix: relating to)