Mid 17th century; earliest use found in John Wilkins (1614–1672), theologian and natural philosopher. From post-classical Latin planarius on level ground, level from classical Latin plānum + -ārius.
Definition of planary in US English:
planary
adjectiveˈpleɪn(ə)ri
rare
Planar.
Origin
Mid 17th century; earliest use found in John Wilkins (1614–1672), theologian and natural philosopher. From post-classical Latin planarius on level ground, level from classical Latin plānum + -ārius.