The word 'square' traces its lineage back to the Latin term 'quadrus', meaning 'a square', which is intrinsically linked to 'quattuor', the number four, reflecting the shape's defining characteristic. It entered English via Old French 'esquarre', a term used in geometry and carpentry, shedding its initial 'e-' over time. The geometric meaning naturally extended to describe town plazas, tools, and the concept of fairness, implying straightness and right angles. Thus, from the simple notion of a four-sided figure, 'square' evolved to encompass a rich set of meanings related to form, space, and moral uprightness.

The word 'square' is a simplex form derived from Old French 'esquarre', which itself came from Vulgar Latin 'exquadra', a noun based on Latin 'exquadrare' meaning 'to square'. The Latin root combines the prefix 'ex-' (out) and 'quadrus' (a square), from 'quattuor' (four).