THESAURUS
abatement, abridgment, allayment, alleviation, analgesia, anesthesia, anesthetizing, appeasement, assuagement, attenuation, attrition, blunting, calming, concavity, contraction, curtailment, cut, cutting, dampening, damping, de-escalation, deadening, debasement, decrease, decrement, decrescence, deduction, deflation, degradation, demotion, demulsion, depletion, depreciation, depression, derogation, descent, detraction, detrusion, diminishment, dip, disparagement, ducking, dulcification, dulling, dying, dying off, ease, easement, easing, extenuation, extraction, fade-out, falling-off, hauling down, hollowness, hushing, impairment, languishment, leniency, lessening, letdown, letup, lightening, loosening, lowering, lulling, miniaturization, mitigation, modulation, mollification, numbing, pacification, palliation, quietening, quieting, reduction, relaxation, relief, remedy, remission, retraction, retrenchment, sagging, salving, scaling down, shortening, shrinkage, simplicity, sinking, slackening, softening, soothing, subduement, submergence, subtraction, tempering, thrusting under, tranquilization, truncation, weakening
ROGET THESAURUS
Decrease
N
nonincrease, decrease, decrease,
diminution, lessening, subtraction, reduction, abatement, declension, shrinking (contraction, ), coarctation, abridgment, extenuation, subsidence, wane, ebb, decline, ebbing, descent, decrement, reflux, depreciation, deterioration, anticlimax, mitigation, unincreased, decreased, decreasing, on the wane, a gilded halo hovering round decay, fine by degrees and beautifully less.
Contraction
N
contraction, reduction,
diminution, decrease of size, defalcation, decrement, lessening, shrinking, compaction, tabes, collapse, emaciation, attenuation, tabefaction, consumption, marasmus, atrophy, systole, neck, hourglass, condensation, compression, compactness, compendium, squeezing, strangulation, corrugation, astringency, astringents, sclerotics, contractility, compressibility, coarctation, inferiority in size, contracting, astringent, shrunk, contracted, strangulated, tabid, wizened, stunted, waning, neap, compact, unexpanded &c (expand), contractile, compressible, smaller &c (small).