Words related to extreme

exterior (adj.)

"situated or being outside, pertaining to or connected with that which is outside," 1520s, from Latin exterior "outward, outer, exterior," comparative of exterus "on the outside, outward, outer, of another country, foreign," itself a comparative of ex "out of" (see ex-). As a noun, "outer surface or aspect" from 1590s.

extremely (adv.)
1530s, from extreme + -ly (2). Originally "with great severity," later more loosely, "in extreme degree" (1570s).
extremeness (n.)

"quality of being extreme, tendency to extremes," 1520s; see extreme (adj.) + -ness.

extremism (n.)

"disposition to go to extremes in doctrine or practice," 1848, from extreme + -ism.

I would remind you that extremism in the defense of liberty is no vice! And let me remind you also that moderation in the pursuit of justice is no virtue. [Barry Goldwater (1909-1998), acceptance speech as Republican candidate for President, 1963]
extremist (n.)
"one who goes to extremes, a supporter of extreme doctrines," 1840, from extreme + -ist.
extremity (n.)
late 14c., "one of two things at the extreme ends of a scale," from Old French estremite (13c.), from Latin extremitatem (nominative extremitas) "the end of a thing," from extremus "outermost;" see extreme (adj.), the etymological sense of which is better preserved in this word. Meaning "utmost point or end" is from c. 1400; meaning "limb or organ of locomotion, appendage" is from early 15c. (compare extremities). Meaning "highest degree" of anything is early 15c. Related: Extremital.
in extremis 
"at the point of death," 16c., Latin, literally "in the farthest reaches," from ablative plural of extremus "extreme" (see extreme (adj.)).