adjective. 
                    Of, pertaining to, or containing, niter; of the quality of niter, or resembling it.
                  
                
                  
                    adjective. 
                    Of, pertaining to, or designating, any one of those compounds in which nitrogen has a relatively lower valence as contrasted with nitric compounds.
                  
                
                  
                    adjective. 
                    a hypothetical acid of nitrogen HNO2, not known in the free state, but forming a well known series of salts, viz., the nitrites.
                  
                
                  
                    adjective. 
                    See Laughing gas.