My personal definition would be "authoritarian communist (or """communist""") regime supporters/apologists". I think a good litmus test is, if the topic of the Tiananmen Square massacre comes up, and their first input is "Ok, but, how many zeroes did the number of dead civilians really have", they're probably too far gone to bother engaging much with
Too many anarchist/commune types consider the authoritarians to be their allies because they also hate the capitalists, right up until the point they're next on the list of undesirables destined for the wall