What are the best answers for “an extreme conservative; an opponent of progress or liberalism”?

reactionary, ultraconservative.

How many letters does the top answer for “an extreme conservative; an opponent of progress or liberalism” have?

The most common answer is reactionary (11 letters).

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

reactionary 11 letters wn-def

an extreme conservative; an opponent of progress or liberalism

ultraconservative 17 letters wn-def

an extreme conservative; an opponent of progress or liberalism