the GNU version of the Collaborative International Dictionary of English
n. A name sometimes given to the nitro group or radical.
The Century Dictionary and Cyclopedia
n. Nitric, peroxid (NO2), a univalent radical assumed to exist in nitric acid and in the so-called nitro-compounds.
Word Usage
"The nitro-explosives consist generally of some organic substance in which the NO_ {2} group, known as nitryl, has been substituted in place of hydrogen."