[1] : WordNet (r) 2.0

hadean
     adj : of or relating to or characteristic of hades or tartarus
           syn: plutonian, tartarean
     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 time, hadean eon, hadean aeon, priscoan,
          priscoan eon, priscoan aeon
see also:
plutonian tartarean hadean time hadean eon hadean aeon priscoan 
priscoan eon priscoan aeon 

Hadean >> H Words
Hadean, definition of term: Hadean
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