I've written here before that the word "reactionary" acts as a warning sign to me that the person using it probably shouldn't be taken seriously on the point in question. I saw an example of that today listening to a history of the Supreme Court by Prof. Peter Irons of USCD. Commenting on the Supreme Court case of Adkins versus Children's Hospital 1923 Irons says that the decision of the court to strike down a minimum-wage law was "so reactionary that even Chief Justice Taft dissented."
Now in the context of Marxist historical doctrine, the word "reactionary" makes some sense. But taken out of that context it is really little more than an equivalent of "yuck!" One calls whatever policies or positions that stand in the way of a leftward-moving agenda "reactionary." What is ironic in this case is that, of course, the legal regulation of market prices far, far predates the laissez-faire doctrine that the court was using in making their decision. While Prof. Irons holds that the court was "going back" to the late-19th century in making their decision, the kind of law he's supporting in this case is actually "going back" to the Middle Ages. Therefore it was far more reactionary, if one wishes to use that kind of silly terminology, than was the court's decision.
The above constitutes no argument against minimum-wage laws, of course, once one abandons the fatuous notion that history is always moving forward in some "progressive" fashion.