Wikipedia seems to disagree, actually. It is used to refer both to a political strawman, and to a legitimate school of thought - which need not have political implications persay[1]. The generally used label seems to be "critical theory", or even "theory" for short (talk about ambiguity!); which definitely includes Marxist ideas in addition to other stuff.

[1] Considering how ubiquitous the use of Marxian theory is in the humanities and social sciences, expecting everyone who uses such theories to be a radical socialist is kind of like expecting all business or econ professors to be extreme conservatives or libertarians.