This is a real thing. You can have two people speaking what sounds like the same language but it's completely different. There could be very real money in writing a serious dictionary between the two like you would have a French dictionary.

It's impossible to have a single dictionary anymore for English. You need multiple dictionaries because it's at least two divergent languages but that derive from the same lexicon.

Many academic fields also have their own jargon where they routinely repurpose words. This is a significant problem in accessibility to a lot of fields because they talk in what looks like plain English but it makes no sense what it refers too. There is a huge deficit when it comes to producing dictionaries for these variants of English.

A lot of people would be shocked to see a dictionary of terms to see what it is people on the left wing who believe in social justice really mean by things like white supremacist or homophobe. It would make the extremism very apparent. Sometimes they're mislabelling things but other times they are speaking a different language where those words mean something different and in that context they're using them appropriately where as what isn't appropriate is their belief system.

Homophobe for example means someone who is afraid of being gay. Thus if you do not admit to being gay then you are a homophobe.