'macrofauna' originates from Greek and Latin: the prefix 'macro-' comes from Greek 'makros' meaning 'large', and 'fauna' comes from Latin 'fauna' meaning 'animal life.'

'macrofauna' was created in modern scientific English by combining the Greek-derived prefix 'macro-' with Latin 'fauna' (itself used in classical Latin); the compound arose in ecological and zoological literature in the 19th–20th centuries to denote larger animal groups.

Initially a literal compound meaning 'large animals,' it developed as a technical ecological term specifically referring to animals above a certain size class (distinguished from meiofauna and microfauna); the core sense of 'larger animals' has remained.