This has long been a puzzle word in Masonic nomenclature. How, it is asked, can a square be oblong, when a square is equal on all its sides? The answer is that in this connection “square” is used in the sense of rectangle; the angles are squared, not the sides. Oblong is derived from ob, near, or before, and longus, long; that is, it means something approximately long, so that the main axis is much longer than the others, as a slender leaf, a shaft, etc. An “oblong square is a rectangle of which two opposite sides are much longer than the other two. The Lodge symbolically is an oblong square in this sense.
- Source: 100 Words in Masonry
A parallelogram, or four-sided figure, all of whose angles are equal, but two of whose sides are longer than the others. Of course the term oblong square is strictly without any meaning, but it is used to denote two squares joined together to form a rectangle.
Brother Sir Walter Scott (in chapter vii of his novel Ivanhoe) has a description of a tournament and tells of the enclosures forming a space of a quarter of a mile in length, and about half as broad. The form of the enclosure was an oblong square, save that the corners were considerably rounded off in order to afford more convenience for the spectators."
Brother C. C. Hunt (Builder, volume ii, page 128), says it is the survival of a term once common but now obsolete; that at one time the word square meant right-angled, and the term a square referred to a four sided figure, having four right angles, without regard to the proportionate length of adjacent sides. There were thus two classes of squares; those having all four sides equal, and those having two parallel sides longer than the other two. The first class was called perfect squares and the second class ob1t squares.
This is the symbolic form of a Masonic Lodge, and it finds its prototype in many of the structures of our ancient Brethren. The Ark of Noah, the Camp of the Israelites, the Ark of the Covenant, the Tabernacle, and, lastly, the Temple of Solomon, were all oblong squares.