1. A combining form or prefix meaning relating to the presence of niter.

2. <chemistry> 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.

Synonyms: nitroxyl.

(29 Oct 1998)