combining form
or diazo-
Etymology: International Scientific Vocabulary, from di- + az-
1. usually diazo- : containing the group N 2 united to carbon in one organic radical
diazo acetic ester N 2 CHCOOC 2 H 5
2. diazo- : containing diazonium
diazo benzenesulfonic acid + N 2 C 6 H 4 SO 3 -