'apod' originates from New Latin, specifically the taxonomic term 'Apoda'/'Apodiformes', where Ancient Greek 'apous' (ἀπούς) meant 'without feet' (from prefix 'a-' meaning 'without' + 'pous' meaning 'foot').

'apous' (Greek) was Latinized in scientific New Latin as 'Apoda' or incorporated in 'Apodiformes'; from these scientific/formal usages the English form 'apod' developed as a noun referring to members of that group.

Initially it described the characteristic 'without feet' (or having very small feet); over time it became a taxonomic/common name for birds of the Apodiformes (swift-like birds).