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.
© Webster 1913.