Precambrian

Pre·cam·bri·an  (pr-kmbr-n)

adj.

Of or belonging to the geologic time period between Hadean Time and the Cambrian Period, often subdivided into the Archean and Proterozoic eras, comprising most of the earth's history and marked by the appearance of primitive forms of life. See Table at geologic time.

n.

The Precambrian Eon.

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Precambrian, Pre-Cambrian [priːˈkæmbrɪən]

adj

(Earth Sciences / Geological Science) of, denoting, or formed in the earliest geological era, which lasted for about 4 000 000 000 years before the Cambrian period

n

(Earth Sciences / Geological Science) the. the Precambrian era See Archaeozoic, Proterozoic

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Precambrian  (pr-kmbr-n, -km-)

The period of geologic time between Hadean Time and the Phanerozoic Eon, from about 3.8 billion to 540 million years ago. During the Precambrian Eon, which is divided into the Archean and Proterozoic, primitive forms of life first appeared on Earth. See Chart at geologic time.

Thesaurus

Noun

1.

Precambrian - the eon following the Hadean time and preceding the Phanerozoic eon; from about 3,800 million years ago until 544 million years ago Precambrian aeon, Precambrian eon, Precambrian period Proterozoic, Proterozoic aeon, Proterozoic eon - from 2,500 to 544 million years ago; bacteria and fungi; primitive multicellular organisms Archaeozoic, Archaeozoic aeon, Archean, Archean aeon, Archean eon, Archeozoic, Archeozoic eon - the time from 3,800 million years to 2,500 million years ago; earth's crust formed; unicellular organisms are earliest forms of life