Sasha Volokh has a great post on the definition of "semi-automatic weapon." It drives me crazy too when people use that term as if it means virtually the same thing as "automatic." Perhaps gun makers and enthusiasts should just come up with a more descriptive and less pejorative-sounding term to describe all the many guns that shoot one bullet with one pull of the trigger without any pumping action required (but without spraying bullets everywhere, which is what people seem to think when they hear "automatic" even with "semi" in front of it.).