n.
1.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)
Idiom of the Day
bring (something) home to (someone) or bring home (something) to (someone) or bring home to (someone) (something)
to cause someone to realize the truth or importance of something
The dry conditions are bringing home to the farmers the importance of saving water.