Definition from Wiktionary, the free dictionary
lactam (plural lactams)
- (organic chemistry) Any of a class of cyclic amides, that are the nitrogen analogs of lactones, formed by heating amino acids; the tautomeric enol forms are known as lactims.
cyclic amides, nitrogen analogs of lactones
Greek prefixes indicate the ring size e.g. α- 3-membered, β- 4-membered.