Nitro- \Ni"tro-\
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.
{Nitro group}, the radical {NO2}; -- called also {nitroxyl}.