'concavity' originates from Latin, specifically the word 'concavitas' (from 'concavus'), where the prefix 'con-' meant 'together/with' and 'cavus' meant 'hollow'.

'concavity' changed from Latin 'concavitas' through Late Latin and possibly Old French forms into Middle English and eventually became the modern English word 'concavity'.

Initially it meant 'the state of being hollow' from the Latin root, and over time it retained that sense while also gaining specialized uses (for example, the mathematical sense describing inward curvature).