ketu केतु

Definition: m. the dragon's tail or descending node (considered in astronomy as the 9th planet, and in mythol. as the body of the demon saiṃhikeya- [son of siṃhikā-] which was severed from the head or rāhu- by viṣṇu- at the churning of the ocean, but was rendered immortal by having tasted the amṛta-)