'anovulation' originates from modern medical formation: the Greek prefix 'an-' meaning 'without' combined with 'ovulation', which comes from Latin 'ovulum' (diminutive of 'ovum') meaning 'egg'.

'ovulation' came into English via Medieval/Neo-Latin (e.g. Latin 'ovulatio' from 'ovulum' < 'ovum'), and the compound 'anovulation' was formed in modern medical English by prefixing 'an-' to 'ovulation'.

Initially, the root 'ovulation' meant 'the release of an egg'; over time the coinage 'anovulation' came to mean 'the lack or failure of that release'.