The flowing out or escape of something, especially a fluid, gas, or immaterial substance like time or money.
From Latin effluxus, past participle of effluere (to flow out), from ex- (out) + fluere (to flow). The word entered English in the 16th century via scientific and philosophical texts.
The word captures something poetic about time itself—Latin speakers used 'efflux' to describe how time flows away irretrievably, which is why you might read about 'the efflux of years' in older poetry.
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