1. Hadean - Noun
2. Hadean - Adjective
3. Hadean - Adjective Satellite
4. Hadean - Proper noun
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
of or relating to or characteristic of Hades or Tartarus
Source: WordNetHowever, the Lunar geologic timescale embraces several major divisions relating to the Hadean and so these are sometimes used in a somewhat informal sense to refer to the same periods of time on Earth. Source: Internet
There is a recently proposed alternative scale that includes the addition of the Chaotian and Prenephelean Eons preceding the Hadean, and divides the Hadean into three eras with two periods each. Source: Internet