hydrogen cyanide

noun

1

: a poisonous usually gaseous compound HCN that has the odor of bitter almonds

2

: hydrocyanic acid

Examples of hydrogen cyanide in a Sentence

Recent Examples on the Web

This included a witness who claimed that Lizzie Borden had tried to buy prussic acid, a fast-acting poison containing hydrogen cyanide, the day before the murders. — Encyclopedia Britannica, 19 Aug. 2026

Consuming this toxin can release poisonous hydrogen cyanide into the bloodstream. — Carrie Madormo, Verywell Health, 30 June 2026

Fine particles can penetrate deep into people’s bodies, along with gases that include carbon monoxide, styrene gas and hydrogen cyanide. — Ellen M. Considine, The Conversation, 2 June 2026

Celebrations were in full swing as the cloud descended on the metropolis in a thick, deadly fog that, owing to the presence of hydrogen cyanide, smelled of bitter almonds. — Taran Dugal, New Yorker, 23 May 2026

Word History

First Known Use

1869, in the meaning defined at sense 1

Rhymes for hydrogen cyanide

• acetaldehyde
• acetanilide
• arabinoside
• cycloheximide
• cyclophosphamide
• diethylamide
• dinucleotide
• ferricyanide
• ferrocyanide
• glutaraldehyde
• glyceraldehyde
• hydroperoxide

Medical Definition

hydrogen cyanide

noun

1

: a poisonous usually gaseous compound HCN that has the odor of bitter almonds

2

: hydrocyanic acid