Here’s another from the week’s meetings. In a discussion, someone asked this:
How many people are reactionary? Do you respond to problems in a reactionary way?
In the words of Inigo Montoya, “You keep using that word. I do not think it means what you think it means.”
The speaker in the example above was asking whether people wait for problems to happen and then react to them, as opposed to trying to anticipate potential problems and take preventive measures. The word for that is “reactive”.
“Reactionary” is something else.
To be “reactionary” is to be ultra-conservative, to oppose progress, or, indeed, any sort of change, and prefer to go back to how things used to be.
That’s not what the guy was asking about, but it took me a moment to figure out what he was really getting at. I didn’t think he was talking about Teabaggers, but....
Words have meanings for a reason.
 And with “reactive”, context is everything. In chemistry, sodium is reactive and argon is not. In electrical engineering, a reactive circuit is one with a high level of reactance.