Root fallacy?

So their is this koine greek word called ἀποστασία (apostasia) which basically means a defection, revolt, apostasy. Their are some who say this word could also mean a physical departure because of its etymology and where the word comes from. Here is basically how the definition goes according to its etymology "apostasía (from 868 /aphístēmi, "leave, depart," which is derived from 575 /apó, "away from" and 2476 /histémi, "stand") – properly, departure (implying desertion); apostasy – literally, "a leaving, from a previous standing." Heres the thing though, there is 355 occurrences during the koine greek period where this word is used, and out 355 times it is used, it is never once used to mean a physical departure. So obviously there has to be some fallacy here other than just people cant read.

"Their (sic) are some who say this word could also mean a physical departure because of its etymology and where the word comes from. "

This is precisely a  topic for etymologists and NOT logicians. 

et·y·mol·o·gy
/ˌedəˈmäləjē/
noun: etymology
the study of the origin of words and "the way in which their meanings have changed throughout history."

I'm not sure I completely understand your question, but I've been doing some research on the various "definnist" fallacies, so I'll give you my two cents worth of advice.

First, words' definitions change over time. They can also have multiple definitions at any given time.

Using a definition that isn't familiar to other people is a common strategy in politics. It's very deceptive, though it isn't always technically a fallacy.

The fallacy arises when people insist that a particular definition is the correct one, when there may be alternative definitions that are just as good.

For example, the etymological fallacy is in play when someone says a word's original meaning is the correct one, if I'm not mistaken. I call it the "historic definition fallacy."

A propagandist can also focus on current definitions, insisting that one of them is the correct definition. I call this a simple "appeal to definition," though some may use other terms.

Another very deceptive practice is to make up your own definition, a practice sometimes called "redefinition." The best example lies in the realm of conspiracy. There's an army of propagandists who are making up the most bizarre and insulting definitions for the terms "conspiracy" and "conspiracy theory." If you take a close look at them, many are illogical.

Creating your own definition isn't necessarily bad as long as a person is transparent. If you let readers know that a particular word already has six popular definitions, and you just coined a seventh definition that you think works better in some particular situation, that might not be a problem.

However, it sounds like you're talking about something different. It sounds like there is a Greek word that simply has multiple definitions that are creating some confusion. If people aren't using these words in arguments in a deceptive manner, then it wouldn't have anything to do with fallacy.