1exaggerated or uncontrollable emotion or excitement:the anti-Semitic hysteria of the 1890s
2an old-fashioned term for a psychological disorder characterized by conversion of psychological stress into physical symptoms (somatization) or a change in self-awareness (such as a fugue state or selective amnesia).
early 19th century: from Latin hystericus(see hysteric)
hysteria in other Oxford dictionaries
Definition of hysteria in the US English dictionary