No. Single words mean little out of context, and the context for "leftist" is so broad as to be effectively meaningless. Everyone from leftcoms to MLMs to slightly progressive democrats that want to melt the unhoused call themselves leftists. If it has any actual meaning that can be defined in a way that resists being able to play Wittgensteinian word games, it is solely a term meaning "opposed in rhetoric to self-identified non-progressive politics, whatever that means in context." Pretty much every other definition you could give will end up in some sort of no true Scotsman race to the bottom of increasingly radical people saying that some other person "isn't a real leftist."
No. Single words mean little out of context, and the context for "leftist" is so broad as to be effectively meaningless. Everyone from leftcoms to MLMs to slightly progressive democrats that want to melt the unhoused call themselves leftists. If it has any actual meaning that can be defined in a way that resists being able to play Wittgensteinian word games, it is solely a term meaning "opposed in rhetoric to self-identified non-progressive politics, whatever that means in context." Pretty much every other definition you could give will end up in some sort of no true Scotsman race to the bottom of increasingly radical people saying that some other person "isn't a real leftist."