Cryptozoic
Pronunciation: /ˌkrɪptəˈzəʊɪk/
Definition of Cryptozoic
adjective
Geology- relating to or denoting the period (the Precambrian) in which rocks contain no, or only slight, traces of living organisms. Compare with Phanerozoic.
Origin:
early 20th century: from Greek kruptos 'hidden' + zōē 'life' + -ic