exert v.

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.).

Proto-Indo-European root meaning "to line up."

It forms all or part of: assert; assertion; assort; consort; desert (v.) "to leave one's duty;" desertion; dissertation; ensorcell; exert; exsert; insert; seriatim; seriation; series; sermon; serried; sorcerer; sorcery; sort.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit sarat- "thread;" Greek eirein "to fasten together in rows;" Latin serere "to join, link, bind together," series "row, chain, series, sequence, succession;" Gothic sarwa (plural) "armor, arms;" Old Norse sörve "necklace of stringed pearls;" Old Irish sernaid "he joins together;" Welsh ystret "a row."