pīla

Pīla in Latin meant a pier, a pillar, a ball (as in a ball game), and a mortar for pounding. The architectural sense — a vertical support — came from the idea of stacked stones forming a pier. Old French took pīla and produced piler, which entered Middle English as piler, then pillar. Where column carried connotations of Greek elegance and mathematical proportion, pillar was blunter. A pillar held things up. It did not need to be beautiful.

The Bible gave pillar its metaphorical life. The pillar of cloud and pillar of fire that guided the Israelites through the desert (Exodus 13:21) turned the word into a symbol of divine guidance. 'Pillar of the community' appeared in English by the fifteenth century — a person who supports the social structure the way a stone pillar supports a roof. The phrase is so familiar now that it has nearly lost its architectural flavor.

Pillars and columns overlap but are not identical. In architectural terminology, a column is usually cylindrical, often following one of the classical orders, and is structurally load-bearing. A pillar can be any shape — square, octagonal, clustered — and may be purely decorative. In practice, English speakers use the words interchangeably. The distinction matters to architects. It does not matter to most buildings.

The Pillars of Hercules — the ancient name for the Strait of Gibraltar — placed pillars at the edge of the known world. Pindar mentioned them in the fifth century BCE. The phrase meant 'the boundary beyond which you should not go.' The pillars were not actual pillars but rock formations on either side of the strait. The word did not need the structure to carry the metaphor. Pillars mark limits.