'aponeurositis' originates from Modern Latin/medical formation and Ancient Greek, specifically from Greek 'aponeūrōsis' (ἀπονευρώσις) where 'apo-' meant 'away' and 'neuron' meant 'sinew, tendon', combined with the Greek suffix '-itis' which meant 'inflammation'.

'aponeurosis' came from Greek 'aponeūrōsis' into Latin as 'aponeurosis', and in New Latin/medical English the element was combined with the suffix '-itis' to form 'aponeurositis'.

Initially it referred specifically to inflammation of an aponeurosis; this medical meaning has been retained in modern usage.