inhibitor

American  

[in-hib-i-ter] / ɪnˈhɪb ɪ tər /

Or inhibiter

noun

1. a person or thing that inhibits.

2. Chemistry. a substance that decreases the rate of or stops completely a chemical reaction.

3. any impurity in a mineral that prevents luminescence.

4. Rocketry. an inert antioxidant used with solid propellants to inhibit burning on certain surfaces.

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inhibitor British  

/ ɪnˈhɪbɪtə /

noun

1. Also called: inhibiter.  a person or thing that inhibits

2. Also called: anticatalyst.  a substance that retards or stops a chemical reaction Compare catalyst

3. biochem

   1. a substance that inhibits the action of an enzyme

   2. a substance that inhibits a metabolic or physiological process

      a plant growth inhibitor

4. any impurity in a solid that prevents luminescence

5. an inert substance added to some rocket fuels to inhibit ignition on certain surfaces

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Etymology

Origin of inhibitor

First recorded in 1865–70; inhibit + -or ²

Explanation

An inhibitor is a substance or material that slows down or halts some activity. This word is popular in the chemistry lab, but you might also hear it at a garage. For example, a corrosion inhibitor helps slow down rust. When you feel inhibited, you feel self-conscious and less likely to do things. In chemistry, an inhibitor has the effect of squelching something, shutting it down, or slowing it. For example, in a car engine, antifreeze is an inhibitor — it prevents or slows the formation of ice. Different substances are inhibitors for different reactions and activities. Think of an inhibitor as chemistry's way of saying "Slow down!" or "Stop!"

Example Sentences

See Examples For:

inhibitor

Sino Biopharmaceutical said subsidiary Chia Tai Tianqing Pharmaceutical granted AstraZeneca exclusive rights to develop, manufacture and commercialize its new PDE3/4 inhibitor, TQC3721, outside China.

From The Wall Street Journal ● Jul. 8, 2026

One cPLA2 inhibitor emerged as the leading candidate after reducing harmful cPLA2 activation in human brain cells exposed to Alzheimer's-related stress conditions.

From Science Daily ● May 26, 2026

Doctors typically then give a checkpoint inhibitor or targeted drug if patients have a particular mutation, but many still continue to show cancer progression.

From The Wall Street Journal ● Apr. 21, 2026

Key to J&J’s future is Tremfya, an IL-23 inhibitor used to treat several autoimmune conditions, such as plaque psoriasis.

From MarketWatch ● Apr. 14, 2026

Such birds being heterozygous for the inhibitor factor, should be whites showing some coloured "ticks."

From Mendelism Third Edition by Punnett, Reginald Crundall

Related Words

• avoidance