tetrant|ˈtɛtrənt| [ad. L. tetrans, tetrant-em (Vitruv.), ad.Gr. τετρᾶς.] = quadrant n.1 4 (b). 1860Weale Dict. Terms (ed. 2), Tetrants, the four equal parts into which the area of a circle is divided by two diameters drawn at right angles to each other.