a shape with four straight sides of equal length and four angles of 90°; a piece of something that has this shape

used after a unit of measurement to say that something measures the same amount on each of four sides. a carpet four metres square.

1(geometry) having four straight equal sides and four angles of 90° a square room · 2forming an angle of 90° exactly or approximately The book had rounded, not ...

a shape with four straight sides of equal length and four angles of 90°; a piece of something that has this shape

shape. ​square something (off) to make something have straight edges and corners. The boat is rounded at the front but squared off at the back.

There are 50 meanings listed in OED's entry for the noun square, 18 of which are labelled obsolete. See 'Meaning & use' for definitions, usage, and quotation ...

1to make something have straight edges and corners square something It was like trying to square a circle. That is, it was impossible.

(only used after the verb) directly; not at an angle synonym squarely I looked her square in the face. He hit me square on the jaw.

There are 46 meanings listed in OED's entry for the verb square, seven of which are labelled obsolete. See 'Meaning & use' for definitions, usage, and quotation ...

​(only used after the verb) directly; not at an angle synonym squarely. I looked her square in the face. He hit me square on the jaw.