English

Alternative forms

• co-planarity

Noun

coplanarity ‎(countable and uncountable, plural coplanarities)

1. (geometry, of at least two things, usually lines) The state or characteristic of being within the same plane.
2. (astronomy, of multiple planets or other orbiting bodies) The state or characteristic of orbiting a central celestial object within the same orbital plane.
   • 2009, Robert Naeye, "Exoplanets' Dance Reveals They're Coplanar," skyandtelescope.com, 9 Jan. (retrieved 9 Jan. 2009):

     Gliese 876 affords us by far our most detailed and accurate map of any extrasolar planetary system in the solar neighborhood, and . . . it is reassuring to see a kinship in the most fundamental property of system coplanarity.

Related terms

• coplanar