First, some background on where the academic/sociological concept of Critical Race Theory comes from, then I'll address CRT's current invocations directly.
Critical Theory and it's descendants (in this case Critical Theory->Critical Legal Studies->Critical Race Theory) is a sort of methodological approach to talking about sociological, economic, political, and cultural phenomena.
At its core, Critical Theory is about not taking the status quo as a given. Frequently in economics, sociology, psychology, political science, et cetera, a speaker will evaluate propositions based on how much they deviate from a baseline - usually the circumstances going on. E.g. "How much will it cost to forgive $10,000 of student loans per borrower in the United States?"
Critical Theory backs up a step and would approach this same question thusly: "Why is student debt even a thing?" Or perhaps, "What is the cost of allowing students to be burdened with debt?"
In part because of its roots in Marxist thought, but also because it's a useful cognitive tool, Critical Theory's objective is to demand an examination of the status quo - and because human systems are never perfect - this exercise always yields a laundry list of things that are wrong with that status quo and descriptions of the systems that contribute to those flaws. This leads to the dominant common theme in the bodies of work done in Critical Theory, Critical Legal Studies, and Critical Race Theory:
The status quo benefits someone, and that person has a vested interest in maintaining it.
(It should be fairly apparent why this framework was the best available foundation for Marx's philosophy.)
Critical Race Theory examines the structure of society and focuses on the flaws that contribute to consistent, systematic differences in the socioeconomic and political outcomes for citizens that correlate with race. It gathers evidence of the systems and structures that produce those differences in outcomes and classifies them as "White Supremacism."
In popular language, the shorthand to describe Critical Race Theory is to say that it is the school of thought that begins with:
White Supremacy exists, benefits someone, and that person has a vested interest in maintaining it.
In scholarly reality, there's huge tracts of nuance in there - some structures of White Supremacy are intentional and deliberate (slavery, segregation), some are merely deliberate (SAT scoring - yes, really. I worked for a time as an SAT Prep instructor for The Princeton Review, it's a widely understood phenomena in the industry), and some are vestigial or otherwise unintended side effects of something else. But in common conversation and media where every word has a cost to it, that nuance is universally elided. White Supremacy, in common media, is Nazis, Skinheads, the KKK, etc.
Well intentioned people can try to describe racial disparities in systemic outcomes as "racist systems" - a term which is not inaccurate, but as a term is open to be misunderstood by a listener or reader. What tends to follow is the Fallacy of Division where the listener assumes that if a given societal structure or system is racist, everyone who participates in it must therefore also be equally, and concomitantly racist - and therefore they are being called racist. And since racism is held as a moral failing in a person, they disengage from the conversation's merits and respond defensively to a perceived insult.
That's an agonizingly complex enough situation. Now enter the ill-intentioned.
I won't name names, but it is an empirical fact that Neonazis, the KKK, and other militantly white supremacist organizations and ideologies exist. Moreover, they exist on a spectrum ranging from the prototypical synagogue shooter, through political opportunists who see value in courting people through appeals to their sense of having been cast as morally defective ("racist"), to people chanting slogans with no understanding of the context or history of what things like "you will not replace us" actually mean.
Trolling has evolved from a malevolent internet hobby to a toolkit of deliberate, rhetorical tactics employed even at the institutional level by whole media entities for the purpose of interfering with discourse that might lead to political, social, or behavioral shifts away from a status quo that they desire to support. (Similar to how tobacco companies and oil companies produced bodies of bogus research to ward off science's discovery that their products had powerfully negative impacts on people.)
To answer the question "What does 'Critical Race Theory' mean?" in a given context, therefore, we would need to know the exact context, exact speaker, and if possible their rhetorical intentions. But it exists somewhere on the spectrum from an academic talking about systemic disparities that attach to race, through someone tossing in a buzzword while they decry police brutality, all the way to an actual trolling attempt in order to discredit the term 'Critical Race Theory' so as to eliminate it as a possible avenue to discuss those systemic disparities mentioned in the first case.