'nonovulatory' originates from Modern English, specifically formed from the prefix 'non-' (meaning 'not') and the adjective 'ovulatory', where 'ovulatory' ultimately derives from Latin 'ovum' meaning 'egg'.

'ovum' (Latin) gave rise to verbs/forms meaning 'to produce or relate to an egg' (e.g. Medieval/Modern Latin 'ovulare' / 'ovulate'), which entered English as 'ovulate' and then the adjective 'ovulatory'; the negative prefix 'non-' was added in Modern English to create 'nonovulatory'.

Initially the Latin root 'ovum' meant 'egg'; from that came meanings related to producing or releasing eggs ('ovulate'); over time the compound 'nonovulatory' came to mean specifically 'not producing or releasing an egg (no ovulation)'.