Simple Definition of reduction

from our Learner's Dictionary

reduction

noun

plural reductions
1
: the act of making something smaller in size, amount, number, etc. : the act of reducing something
a drastic/marked/sharp/significant reduction in size
troop reductions = reductions in the number of troops
cost/price/rate reductions
Many voters want to see some reduction of the deficit.
2
: an amount by which something is reduced
There is a 20 percent reduction on selected items during this sale.

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“Reduction.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/reduction. Accessed 18 Jun. 2026.

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