'apothem' originates from French, specifically the word 'apothème', ultimately from Greek 'apothemē', where the prefix 'apo-' meant 'away from' and the root related to 'tithēmi' meant 'to put, place'.

'apothem' changed from the French word 'apothème' (used in early mathematical texts) and passed into English usage as 'apothem' in modern geometry terminology.

Initially, the element of the word referred to a notion of 'distance away' or 'something placed away', but over time it evolved into the current geometric meaning of 'the perpendicular distance from the center to a side of a regular polygon'.