reduce

verb

ri-DOOS/ɹɪˈd(j)us/UKri-JOOS/ɹɪˈd͡ʒuːs/

Formsreduces, reducing, reduced

19 meanings of reduce

Practice

1
make lessverbtransitive
To make something smaller, less, or weaker.
Like turning down the volume so a sound becomes quieter.
The store reduced its prices after the holidays.
Drivers must reduce their speed near schools.
UsageUse by for how much and to for the new amount: reduce it by half, to ten.
Similardecrease, lower, cut, lessen, diminish
Oppositeincrease, raise, boost, expand
2
simplifyverbtransitive
To change something into a simpler form, or to treat it as if it were only one thing, usually followed by "to".
The teacher reduced the long story to five easy sentences.
Please don't reduce my whole life to one bad mistake.
UsageOften a complaint: it means making something sound simpler than it really is.
Similarsimplify
Note
3
boil downverbtransitive or intransitive
To boil a sauce or liquid so some water cooks away and it gets thicker.
Like leaving a pot of water on the stove until much of it turns to steam.
Reduce the sauce until it coats the back of a spoon.
She reduced the wine to a thick syrup.
UsageSay reduce it by half for how much, or to a syrup for how thick.
Similarthicken, concentrate
Oppositedilute
Note
4
chemistryverbtransitive
To make a chemical gain electrons or lose oxygen during a reaction.
Like the opposite of rusting, where a metal gains back what it had lost.
Hydrogen can reduce copper oxide to pure copper.
The reaction reduced the metal ions in the solution.
Oppositeoxidize
Note

Less common meanings

5
worse stateverbtransitive
To make someone or something end up in a much worse state, such as ruins, tears, or begging.
The fire reduced the house to ashes.
Repeated failures can reduce even a confident person to doubt.
UsageUsed with to: reduced to tears, reduced to ashes.
6
lose weightverbdatedintransitive
To lose body weight, usually on purpose by eating less.
Similarslim, diet
7
simplify (math)verbtransitive
To make an equation or fraction simpler while keeping its value the same.
Like writing four-eighths as one-half: the same amount, just simpler.
Reduce the fraction to its lowest terms.
You can reduce the fraction 6/8 to 3/4.
UsageYou reduce a fraction to its lowest terms, like 6/8 to 3/4.
Similarsimplify
Note
8
demoteverbtransitive
To move someone down to a lower rank or position.
Like a team captain being moved back to an ordinary player.
The army reduced him to a lower rank after the incident.
They may reduce her to a junior post next month.
Similardemote, downgrade, degrade
Oppositepromote
Note
9
conquerverbtransitive
To defeat and gain control over an enemy, city, or fortress.
Like winning a long tug-of-war and forcing the other side to give up.
The army reduced the fortress after a long siege.
They planned to reduce the rebel stronghold by winter.
Similarsubdue, conquer, capture, take
10
set a boneverbtransitive
To put a broken or dislocated bone back into its correct place.
Like clicking a puzzle piece back into the spot where it belongs.
The doctor will reduce the broken bone before putting on a cast.
Nurses helped reduce his dislocated shoulder in the emergency room.
Similarset
Note
11
say weaklyverbtransitive
To say a sound or word with less effort, so it becomes weaker or shorter.
Like saying 'gonna' instead of 'going to' because it takes less work.
Many speakers reduce the vowel in unstressed syllables.
People talking fast often reduce the word 'and' to a short 'n' sound.
Similarweaken, shorten
Note
12
extract metalverbtransitive
To get metal out of ore, the rock it is found in, usually by heating it to remove other elements.
Like cooking a rock until the shiny metal inside melts and separates out.
Smelters reduce iron ore to make pure iron.
Workers reduced the copper ore in a huge furnace.
Similarsmelt
Note
13
put in writingverbtransitive
To put something into written form, especially an agreement or a spoken promise.
Like writing down a promise so no one can forget what was said.
The lawyer asked them to reduce the agreement to writing.
Both parties agreed to reduce their spoken deal to a signed contract.
UsageMostly in reduce to writing. In everyday English, say put in writing.
Note
14
translateverbobsoletetransitive
To turn a book or document into another language.
Note
15
verb
To change one problem into another, so that solving the second would also solve the first.
16
verb
To change a syllogism, a kind of logical argument, into a clearer or simpler standard form.
17
verbarchaic
To remove someone from a list of paid workers or soldiers.
18
verbhistorical
To change soldiers from a square block back into a line or column.
19
verbScots law
To cancel something officially through the law, so it no longer counts.

Practice

Can you tell the meanings of reduce apart? Answer 3 quick questions from this page, or write your own sentence and AI will check it.

Origin

From Latin reducere, meaning to lead back, from re- ("back") and ducere ("lead"). It reached English through Old French and Middle English.

Checked 5 Nov 2026 · 4 facts

Reduce derives ultimately from Latin reducere. en.wiktionary.org
Latin reducere means to lead back. en.wiktionary.org
The Latin word combines re-, meaning back, and ducere, meaning lead. en.wiktionary.org
The word passed through Old French and Middle English into modern English. en.wiktionary.org