exonerate 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.).

"a burden," 1640s, from Latin onus "load, burden," figuratively "tax, expense; trouble, difficulty," from PIE *en-es- "burden" (source of Sanskrit anah "cart, wagon"). Hence legal Latin onus probandi (1722) "the task of proving what has been alleged," literally "burden of proving."

"act of exonerating or of discharging or freeing; state of being discharged or freed from an accusation, obligation, debt, etc.," 1630s, from Late Latin exonerationem (nominative exoneratio) "an unloading, lightening," noun of action from past-participle stem of exonerare "free from a burden" (see exonerate).