1. (n.) The state of becoming gradually less; decrease; diminution; waste; loss.

2. (n.) The quantity lost by gradual diminution or waste; -- opposed to increment.

3. (n.) A name given by Hauy to the successive diminution of the layers of molecules, applied to the faces of the primitive form, by which he supposed the secondary forms to be produced.

4. (n.) The quantity by which a variable is diminished.

abatement ablation abridgment alleviation attenuation attrition consumption contraction corrosion curtailment cut cutting dampening damping decrease decrescence deduction deflation deliquescence depletion depreciation depression derogation detraction diminishment diminution dip disparagement dissipation dissolution drain dying dying off erosion evaporation exhaustion expenditure extenuation extraction fade-out impairment impoverishment languishment leakage lessening letup loss lowering miniaturization minus mitigation reduction relaxation remission retraction retrenchment sagging scaling down shortening shrinkage simplicity subtraction truncation using using up wastage waste weakening wear and tear wearing wearing away