Tetragon
Tetragon , noun
[Latin tetragonum, Greek tetra`gwnon; te`tra- (see Tetra-) + gwni`a corner, angle: compare French tétragone.]
1.
(Geometry) A plane figure having four sides and angles; a quadrangle, as a square, a rhombus, etc.
2.
(Astrology) An aspect of two planets with regard to the earth when they are distant from each other ninety degrees, or the fourth of a circle. — Hutton