Comparative form of extreme: more extreme(adjective)
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Use "extremer" in a sentence
"The religious are splitting between these two, with the extreme getting extremer, and moderate generally choosing between the extreme right and the moderate left."
"Mr Senior had seen its essential principle, the right of subsistence, worked out farther -- to extremer and more dangerous consequences -- than perhaps any other political or social experiment, before the practical common sense of England interfered."