Second Exodus
From Battlestar Wiki, the free, open content Battlestar Galactica encyclopedia and episode guide
The Second Exodus is a term used in official documentation from the Colonial Government to describe the exodus from Cylon-occupied New Caprica (Collaborators).
It is unclear whether a "First Exodus" refers to the exodus from Kobol over 2,000 years prior, or the flight from the Twelve Colonies after the Cylon attack.