As promised, I'm back with more motality talk. The two previous posts have already had the natural responses that make this section necessary. After reading it, I hope you'll agree that subjectivity is the bane of moral social progress.
The most common confusion I encounter when discussing morality is that between morality, morals, and ethics. This is usually corrected when we look at the definitions of these words:

The second definition of morals is the one relevant to our discussion.

As we can see, morals and ethics differ significantly from objective morality. They're completely subjective! Morals are your personal code. Ethics are a moral code imposed by an outside factor. That factor could be your workplace, your school, or even the person that owns the home you rent.
So each is based on an outside interpretation of morality. One is your own, one is someone else's, and neither are likely objective.
An obvious but extreme example of subjective morality is the actions of the SS during the reign of Nazi Germany. You won't find a credible source on Earth that can objectively justify genocide. But it was ethical according to Naziism. Without an objective morality to appeal to, the Nazis did nothing wrong. An absurd notion.
What about pedophilia? Rape? Perhaps marginally less extreme than Naziism, and perfectly allowable by the morals of some. Without an objective morality to appeal to, it's perfectly fine to have sexual relations with anyone at all, regardless of consent. How would you like to be the lawyer for Brock Turner, or the judge that sentenced him?
While many morals and ethics may not allow for such egregious actions, if your entire basis of right and wrong is subjective and varried by situation, you give yourself no allowance for defense of self or property. Either intellectually or physically. There can be no right or wrong if right and wrong are judged individually. That is the need of objectivity. That is why there are no synonyms for morality. There is no substitute.
If you want to win, if you want to be right, you must be objective. And if you are objective, you cannot lose.
Stay relevant y'all
Nate