Definition - What does Raksha mean?
Raksha is a Sanskrit root word that has many derivatives. It can be used broadly to mean to guard against evil, to protect, or to be aware of a villain or demonic force. The term occurs frequently in Vedic literature where it is used to refer to the evil forces trying to destroy humanity. For example, in the "Rig Veda," raksha is used to address a group of bad habits and mental disturbances called vritti. These disturbances include the ego and negative emotional states like anger, envy or attachment.
Yogapedia explains Raksha
A related term, rakshasa, means "demon" in Sanskrit; and in Hindu mythology, rakshasa were demonic creatures that had a thirst for blood and ate human flesh. They are said to have been created from Brahma's breath while he was sleeping and immediately started eating the god. To protect himself, Brahma screamed "Rakshama!," meaning "Protect me!" Lord Vishnu came to help him and banished all the rakshasa.
One of the most famous of the rakshasa was Ravana, a 10-headed demon from the epic poem, "Ramayana."