The ninth day of Navratri is dedicated to Goddess Siddhidatri. Siddhi means supernatural power or meditative ability, and Dhatri means giver.
Siddhidatri or Siddhidayani is the Goddess of wisdom. She fulfills the wishes of her devotees and endows them with intellect and wisdom. She has four arms and uses the lion as her vehicle.
Siddhidatri sits on a lotus and rides a lion. She has four arms and holds a lotus, mace, Chakra and shankha. She is surrounded by Gandharvas, Yakshas, Siddhas and Asuras, who worship her.
It is believed that one side of Lord Shiva’s body is that of Goddess Siddhidatri. Therefore, he is also known by the name of Ardhanarishwara.