in the extreme Definition

extreme
adj extremer, extremest

1. Very high, or highest, in degree or intensity.

Thesaurus: utmost, exceptional.
2. Very far, or furthest, in any direction, especially out from the centre.

Thesaurus: remote, outermost, farthest.
3. Very violent or strong.
4. Not moderate; severe.

Example: extreme measures
Thesaurus: intemperate, immoderate, imprudent, excessive, inordinate, unreasonable, radical.

noun

1. Either of two people or things as far, or as different, as possible from each other.
2. The highest limit; the greatest degree of any state or condition.

Thesaurus: limit, ultimate, utmost, climax, extremity, top, edge, end.

Derivative: extremely
adverb

To an extreme degree.

Idiom: go to extremes

To take action beyond what is thought to be reasonable.
Thesaurus: be excessive, be immoderate, go too far, overdo things, go overboard.

Idiom: in the extreme

To the highest degree.

Etymology: 15c: from Latin extremus, from exterus on the outside.