Although distinguished when they act as ligands for transition metals, the names amides (a compound with the general formula RC(=O)NRR) and imidic acids are synonyms describing the same anion.
However, they are distinguished when they act as ligands for transition metals, with O-bound species referred to as imidates and N-bound species referred to as amidates. An amidate/imidate anion is formed upon deprotonation of an amide or imidic acid. The two names are thus synonyms describing the same anion, although arguably, imidate refers to the resonance contributor on the left, while amidate refers to the resonance contributor on the right. 
