What does amidogen mean?
The definition of amidogen
A*mid”o*gen, n.
Etym: [Amide + -gen.] (Chem.)

A compound radical, NH2, not yet obtained in a separate state, which may be regarded as ammonia from the molecule of which one of its hydrogen atoms has been removed; — called also the amido group, and in composition represented by the form amido.