Most remote in any direction; outermost or farthest: the extreme edge of the field. Being in or attaining the greatest or highest degree; very intense: extreme pleasure; extreme pain. Extending far beyond the norm: an extreme conservative. See Synonyms at excessive. Of the greatest severity; drastic: took extreme measures to conserve fuel. Biology Characterized by severe, usually oxygen-poor environmental conditions. Biology Having an affinity for such conditions: an extreme microorganism. Sports Very dangerous or difficult: extreme rafting. Sports Participating or tending to participate in a very dangerous or difficult sport: an extreme skier. Archaic Final; last. The greatest or utmost degree or point. Either of the two things situated at opposite ends of a range: the extremes of boiling and freezing. An extreme condition. An immoderate, drastic expedient: resorted to extremes in the emergency. Mathematics The first or last term of a ratio or a series. Mathematics A maximum or minimum value of a function. Logic The major or minor term of a syllogism.