Illustrated Glossary of Organic Chemistry

Amide: (1) A functional group characterized by the N-C=O moiety. An amide whose carbonyl group is bonded to both an amino group and a hydrogen is called a formamide (i.e., it is a derivative of formic acid).

General amide structure
N,N-Dimethylformamide (DMF)

A primary (1o) amide
A secondary (2o) amide
A tertiary (3o) amide
A formamide

(2) A molecule containing a nitrogen atom with a negative formal charge (i.e., a nitranion).

Sodium amide
Lithium diisopropyl amide