azo-

American Heritage® Dictionary of the English Language, Fourth Edition

1. Containing a nitrogen group, especially one attached at both ends in a covalent bond to other groups: azole.

Century Dictionary and Cyclopedia

1. A curt form of azote in compounds.
2. n. Same as azo-, used adjectively without the hyphen.

Wiktionary

1. containing nitrogen

GNU Webster's 1913

1. Applied loosely to compounds having nitrogen variously combined, as in cyanides, nitrates, etc.
2. Now especially applied to compounds containing a two atom nitrogen group uniting two hydrocarbon radicals, as in azobenzene, azobenzoic, etc. These compounds furnish many artificial dyes. See diazo-.

WordNet 3.0

1. adj. relating to or containing the azo radical