To a very great or excessive degree.

comparative form of extreme: more extreme

The degree or property of being extreme.

Of a place, the most remote, farthest or outermost. / In the greatest or highest degree; intense. / Excessive, or far beyond the norm. / Drastic, or of great severity.

The greatest or utmost point, degree or condition. / Each of the things at opposite ends of a range or scale. / (obsolete, plural only) One of the last moments of life. / A drastic expedient.

(archaic) Extremely.

plural of extreme

plural of extremeness

(degree) To an extreme degree.

plural of extremization