Why is it termed "SHORT" WAVE ?

Because it is shorter than medium wave, which in turn is shorter than
long wave - back when these types of radio signals were the commonly
used wavelengths.

Of course, now with microwaves and picowaves, the name becomes much
less meaningful. In fact, the term H(igh) F(frequency), which seems to
have replaced SW for many purposes, is not really accurate either.

Bruce Jensen