An Etymological Dictionary of Astronomy and Astrophysics

A two-dimensional figure that consists of four points connected by straight lines. Same as → tetragon; see also → quadrilateral.

Etymology (EN): L.L. quadrangulum, noun use of neuter of L. quadrangulus, quadriangulus “four-cornered,” from quadr- variant of quadri- before a vowel “four,” akin to quattuor, → four, cognate with Pers. cahâr, as below; → angle.

Etymology (PE): Cahârgušé, cârguš “four-cornered,” from cahâr, câr “four,” cognate with L. quattuor, → four,

• gušé, guš “corner, angle;” Mid.Pers. gôšak “corner.”