An amide is a compound with the functional group RnE(O)xNR'2 (R and R' refer to H or organic groups). Most common are "organic amides" (n = 1, E = C, x = 1), but many other important types of amides are known including phosphor amides (n = 2, E = P, x = 1 and many related formulas) and sulfonamides (E = S, x= 2). The term amide refers both to classes of compounds and to the functional group (RnE(O)xNR'2) within those compounds.
Amide can also refer to the conjugate base of ammonia (the anion H2N–) or of an organic amine (an anion R2N–). For discussion of these "anionic amides," see Metal amides#Alkali metal amides.
The remainder of this article is about the carbonyl-nitrogen sense of amide.
Read more about Amide: Structure and Bonding, Nomenclature, Characterization, Applications and Occurrence, Amide Synthesis, Amide Reactions