a mathematical instrument, called also a geometrical square, and line of shadows: it is frequently an additional member on the face of the common qua- drant, as also on those of Gunter's and Sutton's quadrant.

in astrology, the same with quartile. See Quartile.

in printing, a piece of metal cast like the let- ters, to fill up the void spaces between words, &c. There are quadrats of different sizes, as m-quadrats, n- quadrats, &c. which are, respectively, of the dimensions of these letters.