'atelocardia' originates from New Latin/Neo‑Latin used in medical terminology, specifically from Greek elements 'atelos' and 'kardia', where 'atelos' meant 'incomplete' and 'kardia' meant 'heart'.

'atelocardia' was formed in New Latin from the Greek roots 'atelos' + 'kardia' and was adopted into modern medical English as the term 'atelocardia'.

Initially it meant 'incomplete (or imperfect) heart' in a literal sense derived from the roots, and over time it has retained that specialized medical meaning referring to congenital incomplete development of the heart.