genomic_island
cryptic_prophage
A remnant of an integrated prophage in the host genome or an "island" in the host genome that includes phage like-genes.
SO:0001007
This is not cryptic in the same sense as a cryptic gene or cryptic splice site.
cryptic prophage
http://ecoliwiki.net/colipedia/index.php/Category:Cryptic_Prophage.w
sequence