'azygosis' originates from Greek, specifically from the elements 'a-' and 'zygos' (Greek 'ἄζυγος' / 'azýgos'), where 'a-' meant 'not' and 'zygos' meant 'yoke' or 'pair'.

'azygosis' was formed in New/Medieval Latin and scientific coinage from Greek roots ('a-' + 'zygos') and entered modern English usage as a medical term referring to the state of being unpaired.

Initially it meant 'not yoked' or 'unpaired' in Greek, and over time it has retained that core meaning in modern anatomical and genetic usage as 'unpaired' or 'failure to pair'.