In Lacan's theory, Hysterical Repression is a repression of mental content which reemerges through hysterical symptoms. Lacan saw repression as characterizing one of the three structures of the subject (neurotic, pervertic and psychotic). While the pervertic is characterized with denial and the psychotic with rejection, the neurotic structure is associated predominantly with repression. Lacan calls Hysterical Repression "the return of the repressed" which causes hysteria like symptoms.
see: Lacanian Terminology