[mit.i.gate] vt -gat.ed ; -gat.ing [ME, fr. L mitigatus, pp. of mitigare to soften, fr. mitis soft + -igare (akin to L agere to drive); akin to OIr moith soft--more at agent] (15c) 1: to cause to become less harsh or hostile: mollify "aggressiveness may be mitigated or ... channeled --Ashley Montagu"
2. a: to make less severe or painful: alleviate b: extenuate syn see relieve -- mit.i.ga.tion n -- mit.i.ga.tive adj -- mit.i.ga.tor n -- mit.i.ga.to.ry adj usage Mitigate is sometimes used as an intransitive (followed by against) where militate might be expected. Even though Faulkner used it "some intangible and invisible social force that mitigates against him --William Faulkner" and one critic thinks it should be called an American idiom, it is usu. considered a mistake.