exterior adj.

word-forming element, in English meaning usually "out of, from," but also "upwards, completely, deprive of, without," and "former;" from Latin ex "out of, from within; from which time, since; according to; in regard to," from PIE *eghs "out" (source also of Gaulish ex-, Old Irish ess-, Old Church Slavonic izu, Russian iz). In some cases also from Greek cognate ex, ek. PIE *eghs had comparative form *eks-tero and superlative *eks-t(e)r-emo-. Often reduced to e- before -b-, -d-, -g-, consonantal -i-, -l-, -m-, -n-, -v- (as in elude, emerge, evaporate, etc.).

early 15c., "overt;" by 1590s as "situated or lying outside," from Latin externus "outside, outward" (from exterus; see exterior) + -al (1). This version won out over exterial. Related: Externally.

early 15c., "outermost, farthest;" also "utter, total, in greatest degree" (opposed to moderate), from Old French extreme (13c.), from Latin extremus "outermost, utmost, farthest, last; the last part; extremity, boundary; highest or greatest degree," superlative of exterus (see exterior). In English as in Latin, not always felt as a superlative, hence more extreme, most extreme (which were condemned by Johnson). Extreme unction preserves the otherwise extinct sense of "last, latest" (15c.).