What does MOAB stand for in the game MW3?

M.O.A.B stands for "Massive Ordinance Air Blast." It is also known by its nickname, "Mother Of All Bombs." It is a hidden reward in "Call of Duty: Modern Warfare 3" obtained by sustaining a 25-kill streak without any assistance.

The M.O.A.B. found in "Call of Duty: Modern Warfare 3" is based on the GBU-43/B, a real weapon also known as the M.O.A.B. The GBU-43/B was designed to be the world's most powerful non-nuclear weapon. It weighs 21,000 lbs, contains 8 tons of explosives, and is guided by GPS. Like its counterpart in "Call of Duty: Modern Warfare 3," the real-life M.O.A.B. was designed to be delivered by aircraft.