English

Alternative forms

• Pre-Cambrian

Adjective

Precambrian ‎(not comparable)

1. (informal, geology) Relating to the time and geology dated before the Phanerozoic

Translations

Proper noun

Precambrian

1. (geology) The eon (or supereon) and rock formations dated before 541.0±1.0 million years ago, coinciding with the first appearance of the fossils of hard-shelled animals.

Usage notes

• The International Commission on Stratigraphy, which attempts to standardize the vocabulary of the field, is revising the boundaries between time periods based on physical-science methods rather than the kinds of fossils present.
• The boundary between the Precambrian and the Phanerozoic has been changed from time to time and will be subject to change, as will the eons listed as Hyponyms below.

Synonyms

• (geological eon): Cryptozoic (archaic)

Coordinate terms

• (geological eon): Phanerozoic

Hyponyms

• (geological eon): Hadean, Archaean, Proterozoic - eons

Translations