AGB

Asymptotic Giant Branch, a description for a type of red giant star
Found on http://www.translationdirectory.com/glossaries/glossary142.htm

AGB

Almost Good Bridge
Found on http://www.encyclo.co.uk/local/21662

Agb

In Enochian, Agb is a cacodemon.
Found on http://www.probertencyclopaedia.com/browse/DA.HTM
No exact match found