From Hindupedia, the Hindu Encyclopedia
By Swami Harshananda
Haragaurī literally means ‘Śiva and Pārvatī’.
According to the Kālikāpurāna, Gauri or Pārvatī, the divine spouse of Śiva, once expressed a desire that she should always be with him like a shadow. Śiva suggested that he could give half of his body to her and she should do the same to him. Gaurī bowed down to him, Brahmā, Viṣṇu and merged half of her into his. Thus the Haragauri form took the shape. It is the same as Ardhanārīśvara.
- The Concise Encyclopedia of Hinduism, Swami Harshananda, Ram Krishna Math, Bangalore