English
anoxic event
From anoxic + event.
Proto-Indo-European *gʷem- ‘to come’
…
Latin veniō ‘come’
Latin ēveniō ‘to happen’
Latin ēventus ‘an event’
Middle French event
English event
Today it means
noun A period of time (e.g. in Earth's history) when large expanses of ocean are depleted of dissolved oxygen.
Language periods are conventional ranges, not dates for this word.
Etymograph / anoxic event