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

No matter how much airlines tout their disinfectant policies, aircraft welcome thousands of passengers daily, with only quick refreshes in between each voyage. —Jillian Dara, Travel + Leisure, 17 Apr. 2026

Founded in 1929, the formula was developed by a chemist who leveraged the disinfectant and deodorizing properties found in pine oil. —Mary Cornetta, Better Homes & Gardens, 17 Apr. 2026

This magnitude of failure, however, can serve as a disinfectant. —Thomas Drance, New York Times, 15 Apr. 2026

In a similar instance of repeating unfounded scientific claims, the president suggested in 2020 that injecting disinfectants could kill the COVID-19 virus. —Brooke Migdon, PEOPLE, 14 Apr. 2026

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