accumulated benefit obligation 
Aviators Breathing Oxygen 
American Board of Orthodontics 
abortion 
adiabatic Born-Oppenheimer 
Air Base Operability 
American Board of Ophthalmology 
American Board of Otolaryngology 
Annular Beam Oscillator 
antibonding bond orbital 
a system of classifying blood groups b… 
abnormal oocyte 
Abo Akademi University 
acute bowel obstruction 
Admin Base Object 
ADVANCED BYTE-ORIENTED 
Agents of Biological Origin 
Air Base Order 
Air Board Order 
American Board of Opticianry 
antibody 
Applied Benefits Option 
APSA Colombia 
Army Budget Office 
As brokers only 
Assistant Boarding Officer 
Astable Blocking Oscillator 
Asymptotic Bounded Optimality 
Audio Basic Object 
Australian Brandenburg Orchestra