- Containing a nitrogen group, especially one nitrogen atom doubly bonded to another nitrogen atom. Many common dyes contain one or a few of these groups.
- <xref>azote</xref>, <xref>nitrogen</xref>
- Applied loosely to compounds having nitrogen variously combined, as in <xref>cyanides</xref>, <xref>nitrates</xref>, etc.
- Now especially applied to compounds containing a two <xref>atom</xref> <xref>nitrogen</xref> group (-N=N-) uniting two <xref>hydrocarbon</xref> <xref>radicals</xref>, as in <xref>azobenzene</xref> etc.