(law) the partial taking away of the effectiveness of a law; a partial repeal or abolition of a law; "any derogation of the common law is to be strictly construed"
a contraction of economic activity resulting in a decline of prices
(geology) the erosion of soil as a consequence of sand and dust and loose rocks being removed by the wind; "a constant deflation of the desert landscape"
(Christianity) the act of mortifying the lusts of the flesh by self-denial and privation (especially by bodily pain or discomfort inflicted on yourself)