biological weapon

noun

: a harmful biological agent (such as a pathogenic microorganism or a neurotoxin) used as a weapon to cause death or disease usually on a large scale

Examples of biological weapon in a Sentence

Recent Examples on the Web

Lyme disease began as a biological weapon, one theory suggested. — Burkhard Bilger, New Yorker, 29 June 2026

Those could include using the technology to create a biological weapon or destroy critical infrastructure. — Sophia Bollag, San Francisco Chronicle, 13 Oct. 2025

The framers of the BWC were clearly not thinking of mirror life forms, but mirror life could be considered a biological weapon and thereby fall under the convention’s remit. — Liyam Chitayat, Foreign Affairs, 28 Aug. 2025

Ethan is on the hunt for a biological weapon called the Chimera virus as well as its cure, both of which were stolen by rogue IMF agent Sean Ambrose (Dougray Scott). — Will Harris, EW.com, 23 May 2025

Word History

First Known Use

1918, in the meaning defined above

Kids Definition

biological weapon

noun

: a harmful living thing (as a disease-causing bacterium) or something (as a poisonous substance) produced by a living thing that is used as a weapon to cause death or disease

Medical Definition

biological weapon

noun

biological weap·​on -ˈwep-ən 

: a harmful biological agent (as a pathogenic microorganism or a neurotoxin) used as a weapon to cause death or disease usually on a large scale