Noun

• S: (n) eon, aeon (the longest division of geological time)
• part meronym
• has instance
• S: (n) Phanerozoic, Phanerozoic eon, Phanerozoic aeon (the period from about 540 million years ago until the present, a period when abundant life existed)
• S: (n) Precambrian, Precambrian eon, Precambrian aeon, Precambrian period (the eon following the Hadean time and preceding the Phanerozoic eon; from about 3,800 million years ago until 544 million years ago)
• S: (n) Proterozoic, Proterozoic eon, Proterozoic aeon (from 2,500 to 544 million years ago; bacteria and fungi; primitive multicellular organisms)
• S: (n) Archean, Archean eon, Archean aeon, Archeozoic, Archaeozoic, Archeozoic eon, Archaeozoic aeon (the time from 3,800 million years to 2,500 million years ago; earth's crust formed; unicellular organisms are earliest forms of life)
• S: (n) Hadean, Hadean time, Hadean eon, Hadean aeon, Priscoan, Priscoan eon, Priscoan aeon (the earliest eon in the history of the Earth from the first accretion of planetary material (around 4,600 million years ago) until the date of the oldest known rocks (about 3,800 million years ago); no evidence of life)
• direct hypernym / inherited hypernym / sister term
• derivationally related form
• W: (adj) eonian [Related to: eon] (of or relating to a geological eon (longer than an era))
• W: (adj) aeonian [Related to: aeon] (of or relating to a geological eon (longer than an era))
• S: (n) eon, aeon (an immeasurably long period of time) "oh, that happened eons ago"
• direct hypernym / inherited hypernym / sister term
• derivationally related form
• S: (n) eon, aeon ((Gnosticism) a divine power or nature emanating from the Supreme Being and playing various roles in the operation of the universe)