dissociative identity disorder (DID) refers to Disorder in which as many as 100 personalities or fragments of personalities co-exist within one body and mind.
dissociative identity disorder (DID) is formerly known as Multiple Personality Disorder.
Other /More definition:
Dissociative identity disorder (DID) refers to a syndrome in which a person develops more than one distinct identity or personality, each of which can have distinct facial and verbal expressions, gestures, interpersonal styles, attitudes, and even physiological responses