coplane
EnglishEdit
EtymologyEdit
NounEdit
coplane (plural coplanes)
 (mathematics) The dual of a plane.

1980, Jaya Srivastava, Combinatorial Mathematics, Optimal Designs, and Their Applications, page 61:
 In Section 4 we show that any PMD in which a coplane is not the intersection of two hyperplanes is an extension of a projective plane.
