Technically and historically, pistol is an all-encompassing term which includes both REVOLVERS and SELF-LOADERS, i.e. handguns.
Sam Colt referred to his invention as a "revolving pistol."
Thus, there are semi-automatic, or self-loading, pistols and revolving pistols.
Common usage these days is, as usual, imprecise. I agree with you that people tend to drop the "semi-automatic" off of the correct description, which would be "semi-automatic pistol," but that does not make it precise, or either technically or historically accurate.