verb (used with object), ni·tri·fied, ni·tri·fy·ing.
- to oxidize (ammonia, ammonium compounds, or atmospheric nitrogen) to nitrites, nitrates, or their respective acids, especially by bacterial action.
- to impregnate with nitrogen or nitrogen compounds.
- to treat or combine with nitrogen or its compounds.
- (formerly) to convert into niter.
verb -fies, -fying or -fied (tr)
- to treat or cause to react with nitrogen or a nitrogen compound
- to treat (soil) with nitrates
- (of nitrobacteria) to convert (ammonium compounds) into nitrates by oxidation