rectangle (n.)

• biquadrate
• four
• foursome
• quad
• quadrangle
• quadrature
• quadrennium
• quadrilateral
• quadrille
• quadruplet
• quartet
• quatern
• quaternary
• quaternion
• quaternity
• square
• tetrad
• tetragon
• tetragram
• tetragrammaton
• tetrahedron
• tetralogy