411 REFERENCE · Wiktionary
Imbrian
Reference material by Wiktionary contributors. This retains its source identity and is not 411 news reporting.
English
Proper noun
1
en geology A lunar geologic period divided into two epochs: the Early Imbrian (3,850 million to about 3,800 million years ago) and Late Imbrian (3,800 million to about 3,200 million years ago).