extreme vs extremum

extreme and extremum both are nouns.

Word	Noun	Adjective	Verb	Adverb
extreme	Yes	Yes	No	No
extremum	Yes	No	No	No

As nouns, extreme and extremum are synonyms defined as:

extreme and extremum: the point located farthest from the middle of something

Other synonyms of extreme include extreme point.

extreme (noun)	extremum (noun)
the furthest or highest degree of something	the point located farthest from the middle of something
the point located farthest from the middle of something	the most extreme possible amount or value

extreme (adjective)	extremum (adjective)
most distant in any direction
far beyond a norm in quantity or amount or degree; to an utmost degree
of the greatest possible degree or extent or intensity
beyond a norm in views or actions