[1] : WordNet (r) 2.0

hadean aeon
     n : 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
         syn: hadean, hadean time, hadean eon, priscoan,
         priscoan eon, priscoan aeon
see also:
hadean hadean time hadean eon priscoan priscoan eon priscoan aeon 

Hadean >> H Words
Hadean, definition of term: Hadean
hadean_pag1.html

Aeon >> A Words
Aeon, definition of term: Aeon
aeon_pag1.html