a colorless liquid, CClNO, prepared by treating chloroform with concentrated nitric acid, and used in chemical warfare as a poison gas, and in insecticides, fungicides, etc.
See chloropicrin in American Heritage Dictionary 4
(klôrˌə-pĭkˈrĭn, klōrˌ-)
noun
An oily colorless liquid, CCl3NO2, that causes skin, lung, and mucous membrane irritation and is used in tear gas and in dyestuffs, disinfectants, insecticides, and soil fumigants. Also called nitrochloroform.