ni·tro- pref.
1. A combining form or an adjective denoting the presence of niter.
2. Chem. A combining form (used also adjectively) designating certain compounds of nitrogen or of its acids; as nitrohydrochloric, nitrocalcite; also, designating the group or radical NO2, or its compounds, as nitrobenzene (C6H5.NO2).
Nitro group, the radical NO2; -- called also nitroxyl.
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