Reactionary describes someone who strongly opposes change and wants to return to the way things used to be. A reactionary person doesn't just prefer old methods or traditions: they actively resist new ideas and often wish society would go back to an earlier time.

When a school announces it will replace traditional textbooks with tablets, a reactionary teacher might protest loudly and insist the old way was better, refusing to consider any benefits of the change. When a town proposes building a new park where an old building stands, a reactionary neighbor might fight to keep everything exactly as it's always been, even if the park would benefit the community.

Being reactionary is different from being conservative or cautious. A cautious person might say “let's think this through carefully” while a reactionary person says “absolutely not, we should never have changed anything in the first place.” Conservative people often value tradition, but reactionary people take it further by wanting to undo changes that have already happened.

In politics and history, reactionaries have opposed reforms like expanding voting rights, changing educational systems, or updating laws. The term usually carries a critical tone, suggesting someone is being unfairly resistant to change.