abatement - a·bate·ment (ə-bāt′mənt)

n.
1. Reduction in amount, degree, or intensity; diminution.
2. The amount lowered; a reduction.
3. Law The act of reducing something, such as a tax, for some period of time or of eliminating something, such as a nuisance, permanently. https://www.thefreedictionary.com/abatement