That is normal terminology. It’s so normal, odds are you’re not going to find a “definitive source for nomenclature” stating it. Yes, it’s confusing to newbies.
The “full auto” you’re thinking of is rare, and even within that category applies almost exclusively to rifles. The Glock 18 and Atchisson AA-12 are about the only modern non-rifle full-auto arms short of extremely obscure/rare/expensive instances. The pedantic may find exceptions (”there are 3 transferable G18s in the USA! never mind their quarter-million-dollar price tags!”) but most sane people don’t go there, as no new “true automatics” have been available since 1986.
For general discussion, “automatic” means “semi-auto”. And a full-auto normal-sized .45 would be just silly.
Unless your goal was a ventilated ceiling.