decrease

decrement diminish diminution drop-off fall lessen lessening minify reduction step-down

increase

alter alteration amount change change magnitude change of magnitude modification modify physical process process

abate abbreviate abridge alleviation amortisation amortization attrition belittle boil down break bring down casualty circumscribe concentrate confine contract contraction cut cut back cut down cutback decay decelerate declassification decline decoct decrescendo deduction de-escalate de-escalation deflate deflation depletion depreciate depreciation desensitisation desensitization devaluate devaluation devalue devitalisation devitalization die away diminish diminution dip discount drop drop off dwindle dwindle away dwindle down dwindling dwindling away ease off ease up easement easing extenuation fall flag fly foreshorten free fall go down let up limit lour lower lowering minimisation minimise minimization minimize mitigate mitigation moderation narrowing palliation pare pare down price reduction reduce relax relief remit retard reverse split reverse stock split rollback shelter shorten shortening shrink shrinkage shrinking shrivel shrivel up sinking slack slack off slack up slacken slacken off slake slippage slow slow down slow up split down step down subtraction suppress taper tax credit tax shelter thin out trim trim back trim down turn down undervalue vanish vaporize wane waning wastage weaken weakening wither