Definition of militate
: to have weight or effect <his boyish appearance militated against his getting an early promotion>
Is mitigate against correct?
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 usually considered a mistake.
Origin and Etymology of militate
Latin militatus, past participle of militare to engage in warfare, from milit-, miles
First Known Use: 1598
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