Box-shaped, box-like, or otherwise suggestive of boxes (with right angles or at least blunt profiles).
Having four equal sides; square.
Solid, robust.
Pertaining to the International Church of the Foursquare Gospel.
Pertaining to a four-square cipher.
A boxy style of domestic architecture with four rooms to a floor, one of which is usually a stair hall.
A four-square cipher.