A moa is an extinct group of flightless birds that were endemic to New Zealand. They were part of the order Dinornithiformes and there were nine species in total, with the largest species reaching about 3.6 meters in height and weighing about 230 kilograms. The word "moa" is a Polynesian term for domestic fowl, but it was not in common use among the Māori by the time of European contact, likely because the bird it described had been extinct for some time.

It is important to note that "MOA" can also refer to "Minute of Angle," which is an angular measurement used in shooting. A MOA is 1/60th of a degree and spreads about 1 inch per 100 yards. It is used to measure the point of impact on a target by a projectile within a cone of trajectory. MOA is also used to help measure shooting in minutes since a bullet moves in an arc-shaped trajectory. The farther away the target is, the lower the bullet might strike from where it was aimed, which is known as bullet drop. MOA is used as an angular measurement, but it can be translated to linear measurement to reach the target. One MOA is equal to one inch at 100 yards.