'apocarpous' originates from New Latin/Modern botanical Latin, specifically the word 'apocarpus', where the prefix 'apo-' meant 'away, apart' and Greek 'karpos' meant 'fruit (or carpel).'

'apocarpousness' developed from the adjective 'apocarpous' combined with the nominalizing suffix '-ness'; 'apocarpous' itself comes from Greek 'apokarpous' (ἀποκάρπους) -> New Latin 'apocarpus' -> Modern English 'apocarpous'.

Initially it described the condition of having separate fruits/carpels in classical botanical usage; over time it has remained a technical term in botany specialized to describe floral morphology (the condition of separate carpels).