This is an incomplete description. There is a Latin verb salvere, meaning "to be in good health".

The Latin word "hello" is salve, the direct imperative form of salvere. It is a command, not strictly a wish, to be well. It's essentially the exact equivalent of the English expression "farewell". (Except that it means "hello" rather than "goodbye".) And like "farewell", it is understood in the derived meaning, "hello", not in the literal meaning.

You could understand salvtare as meaning "to health someone" (it is technically derived from salvs "health", and not from salvere "to be healthy"), but you could also understand it as meaning "to say 'salve(te)'". It's relevant here that valere also means "to be healthy", and its imperative form vale means "goodbye", but salvtare is never going to refer to saying vale.

Lewis and Short doesn't distinguish the senses "wish health" and "greet"; salvtare does have a more direct health-related sense, but it is "to keep something safe" rather than "to wish something safety".

https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext...

That entry also notes that the sense "keep safe" of salvtare derives from sense I.A. of salvs, '"being safe and sound, health, welfare, safety" in general', while the sense "wish health, greet, salute" derives from sense I.B., '"a wish for one's welfare, a greeting, salutation" in particular'.

(Tangentially, I was charmed by the second citation for salvs I.B.: Non ego svm salvtis dignvs? "Am I not worthy of a hello?")

It seems most likely but the OED (at least in the second edition) says:

>[Note. The conjectured derivation from the phrase how d'ye? is impossible, since the Sc. form would then have been (huːdɪ). On the analogy of Sc. gowdie = goldy, howdy might go back to holdie, an appellative (like brownie, etc.) from hold, friendly, benevolent, kind: cf. F. sage-femme.]

But the OED has many oddities regarding American vernacular and I personally take it with a grain of salt when it comes to this area. It's only definition for "howdy" is as an alternative spelling for "howdie," a midwife and ignores the common US idea of it being "how do you do," but it does include a "see how d'ye" where it includes "howdy" and various other spellings for the sentiment of "how do you do."

In the article this is not too far from "Γειά σου" (yah-soo) and the supposed root as a ferryman hail (halâ). So I guess the "yoohoo" branch of greetings might in fact be related, or otherwise it's an independent rederivation with two common and similar sounds ("yo"/"ho").

"Yello" might probably be a cute combination of yoohoo and hello. Or you could go all the way with Yahallo~.

https://en.wikipedia.org/wiki/William_B._Williams_(DJ)

Attempting to write out something close to what I'm imagining they're trying to get across in plain English:

hell-ah-ooh

It's obviously not universal across the South, but you'll rarely see it outside of the South, so "might suggest you're from..." is probably accurate.

You know why this is, right? Most phone calls these days are spam or otherwise annoyances. Many are literally just seeing if a person picks up. They’re listening to see if you’re a real human being.

The phone system is FUBAR.