Just a PSA: "reactionary" doesn't mean "in reaction to". It specifically refers to opposition to social change ("reject modernity, embrace tradition"), and opposition to liberalism and progressivism in particular, like a conservative over-correction (not just rejecting further changes but a desire to revert to an idealized previous state that never was).

Of course the descriptivist in me would say that "reactionary" can also just mean "in reaction to" if enough people just use it that way and that people have picked up the political term through cultural osmosis and apply it to reactions in general validates this meaning, so make of that what you will.