Kshira Sagara

Kshira – Milk, Sagara – Ocean.

The milk ocean, the cosmic primeval sea on which Vishnu as Narayana rests lying on the world snake.

The milk ocean was churned by Gods and Demons, Samudra Manthan, to get Amrita, the nectar of immortality.

Manthan – to churn; Sagara and Samudra – Ocean.