How about a conservative or a traditionalist?
Not a teacher
No, it's exactly the opposite.
The term "reactionary", in the Arab World, is almost entirely used by socialists and leftists (governments, political parties and individuals). Some communists use it as well - in the past!
It is pronounced "raj'ee" in Arabic, which literally means "going back".
It is used to describe one of the following groups / individuals:
1. Conservatives
2, Traditionalists
3. Fundamentalists (or the So-called "Islamists")
So the opposite would depend on context:-
Conservative -> Liberal?
Traditionalist -> Progressive
Fundamentalist-> Not sure of this one (moderate, nonconformist?)