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

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

Move on to your tub, scrubbing out the disinfectant and using a large cup to rinse away any remaining cleaning product. —Mary Catherine McAnnally Scott, Southern Living, 21 Nov. 2025

The Washington State Department of Health urges people cleaning up around bird feeders and other areas exposed to bird feces to wear gloves and disinfect the area with a mixture of one part bleach to 10 parts water or a commercial disinfectant like Lysol spray. —Jen Christensen, CNN Money, 14 Nov. 2025

Skip the Chlorine Bleach Chlorine bleach is a powerful disinfectant that has also traditionally been used in laundry to brighten whites. —Jolie Kerr, Better Homes & Gardens, 4 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