ketene
noun
ke·tene ˈkē-ˌtēn 
: a colorless poisonous gas C2H2O of penetrating odor used especially as an acetylating agent
also : any of various derivatives of this compound
Word History
Etymology
borrowed from German Keten, from Keton ketone + -en -ene
Note: The term was introduced by Hermann staudinger in "Ketene, eine neue Körperklasse," Berichte der Deutschen Chemischen Gesellschaft, 83. Jahrgang (1905), Band II, p. 1735.
First Known Use
1907, in the meaning defined above
Medical Definition
ketene
noun
ke·tene ˈkē-ˌtēn
: a colorless poisonous gas C2H2O of penetrating odor used especially as an acetylating agent
also : any of various derivatives of this compound