sQUARe and QUARter.
Seriously, you can use either quadralateral, or even tetragon. But square is a specific instance of these, being equilateral + equiangular.
PG also admits 'tetralatron' (4-2patches), and *prismahedron 'patch formed by prism-product', beside *tegmahedron (patch by tegum-product).
The dream you dream alone is only a dream
the dream we dream together is reality.