Business & Finance (2) Slang, Chat & Pop culture (0) Sort results:alphabetical| rank? Rank Abbr.Meaning GBBRGas Blowback Rifle (airsoft) GBBRGreater Baltimore Board of Realtors (Maryland) GBBRGabbro (lithological term) Note: We have 1 other definition forGBBRin our Acronym Attic ...