disinfectant

noun

dis·​in·​fec·​tant ˌdis-in-ˈfek-tənt 

plural disinfectants

: an agent used to disinfect something

especially : a chemical agent that is used especially on hard surfaces and in water (such as drinking water or wastewater) to destroy, inactivate, or significantly reduce the concentration of pathogens (such as bacteria, viruses, and fungi)

Note: Common chemical disinfectants include chlorine, calcium and sodium hypochlorite, iodophor, phenol, ethanol, and quaternary ammonium compounds. Disinfectants are often distinguished from sterilants by having reduced effectiveness against dormant bacterial endospores.

Examples of disinfectant in a Sentence

They use a strong disinfectant on the medical equipment.

Clean the area with disinfectant.

Recent Examples on the Web

Be aware that many disinfectant wipes are not completely effective at killing norovirus, the agency said. —Hannah Poukish, Sacbee.com, 15 Dec. 2025

Unfortunately, the 40% alcohol-by-volume just can’t compare to industrial disinfectants or even to stronger types of alcohol. —Taylor Tobin, Southern Living, 12 Dec. 2025

Dangerous products pulled off store shelves, EPA says The EPA said Chedraui and Smart & Final confirmed the disinfectants were no longer being distributed or sold but did not specify how many Arizona stores received the products. —Rey Covarrubias Jr, AZCentral.com, 9 Dec. 2025

The boys crashed inside, Zain throwing himself face down on a sofa still wearing his bloodied shirt, and Yazid nosing about looking for bandages and disinfectant. —Daniyal Mueenuddin, New Yorker, 23 Nov. 2025

Word History

First Known Use

1837, in the meaning defined above

Rhymes for disinfectant

• expectant
• protectant

Kids Definition

disinfectant

noun

dis·​in·​fect·​ant

dis-ᵊn-ˈfek-tənt

: something (as a chemical) that is able to destroy harmful germs (as bacteria and fungi)

disinfectant adjective

Medical Definition

disinfectant

1 of 2 noun

dis·​in·​fec·​tant -ˈfek-tənt 

: an agent (as a chemical or ultraviolet light) that destroys, inactivates, or significantly reduces the concentration of pathogens (as bacteria, viruses, and fungi) especially on hard surfaces and in water (as drinking water or wastewater)

also : a preparation or formulation containing one or more disinfectants along with additional additives (as water and fragrance)

Note: Common chemical disinfectants include chlorine, calcium and sodium hypochlorite, iodophor, phenol, ethanol, and quaternary ammonium compounds. Disinfectants are often distinguished from sterilants by having reduced effectiveness against dormant bacterial endospores.

disinfectant

2 of 2 adjective

: serving or tending to disinfect : suitable for use in disinfecting