SOMA (Sanskrit for " pressed juice," from the root su, to press), in Hindu mythology the god who is a personification of the soma plant (Asdepias acida), from which an intoxicating milky juice is squeezed. Soma is the Indian Bacchus, and one of the most important of the Vedic gods. All the 114 hymns of the ninth book of the Rig Veda are in his praise. He is celebrated as a dual divinity with Indra, Agni, Pushan or Rudra, in other books. The preparation of the soma juice was a very sacred ceremony, and the worship of the god is very old, soma being identifiable with the Avestan homa, prepared and celebrated in the Indo-Iranian period. The plant's true home is heaven, and soma is drunk by gods as well as men, and it is under its influence that Indra is related to have created the universe and fixed the earth and sky in their place. In post- Vedic literature soma is a regular name for the Moon, which is regarded as being drunk up by the gods and so waning, till it is filled up again by the Sun. In both the Rig Veda and Zend Avesta soma is the king of plants; in both it is a medicine which gives health, long life and removes death. In both the celestial is distinguished from the terrestial soma, and the liquor from the god. The first soma is supposed to have been stolen from its guardian demon by an eagle, this soma-bringing eagle of Indra being comparable with the nectar-bringing eagle of Zeus, and with the eagle which, as a metamorphosis of Odin, carried off the mead.
See A. A. Macdonell, Vedic Mythology (Strassburg, 1897).
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)