biohazard

noun

bio·​haz·​ard ˈbī-ō-ˌha-zərd 

: a biological agent or condition that is a hazard to humans or the environment

also : a hazard posed by such an agent or condition

biohazardous

ˌbī-ō-ˈha-zər-dəs 

adjective

Examples of biohazard in a Sentence

The gasoline spill created a serious biohazard.

Recent Examples on the Web

Moore cautioned people with lung issues or smoke sensitivity to avoid outdoor activities, but said crews have mitigated the hazardous-materials portion of the blaze and are now focused on the biohazard portion posed by spoiled food. — Arkansas Online, 21 June 2026

The potential biohazard posed by millions of pounds of spoiling food is a concern, Kleinman said. — Hayley Smith, Los Angeles Times, 21 June 2026

Authorities said hazardous material risks have largely been mitigated, but the situation is now shifting toward potential biohazard issues as food inside the facility remains unrecovered. — Iris Salem, CBS News, 20 June 2026

Government lawyers have argued that the project includes critical security features to guard against a range of possible threats, such as drones, ballistic missiles and biohazards. — ABC News, 16 Apr. 2026

Word History

First Known Use

1965, in the meaning defined above

Rhymes for biohazard

• haphazard
• hazard

Medical Definition

biohazard

noun

bio·​haz·​ard ˈbī-ō-ˌhaz-ərd, -ˈhaz- 

: a biological agent or condition (as an infectious organism or insecure laboratory procedures) that constitutes a hazard to humans or the environment

also : a hazard posed by such an agent or condition

biohazardous

-ˈhaz-ərd-əs 

adjective