4. (Logic)

Defn: Either of the extreme terms of a syllogism, the middle term being interposed between them.

5. (Math.)

Defn: The first or the last term of a proportion or series. In the extreme as much as possible. "The position of the Port was difficult in the extreme." J. P. Peters.

EXTREMELESS
Ex*treme"less, a.

Defn: Having no extremes; infinite.

EXTREMELY
Ex*treme"ly, adv.

Defn: In an extreme manner or state; in the utmost degree; to the utmost point; exceedingly; as, extremely hot or cold.

EXTREMIST
Ex*trem"ist, n.

Defn: A supporter of extreme doctrines or practice; one who holds extreme opinions.