A syllable, word or phrase with spiritual power, it is chanted or held in the mind in connection with meditation or ritual. Mantras are commonly used by Hindus, Buddhists and Jains and are traditionally drawn from Sanskrit scriptures, such as the Vedas. The adherents of some vernacular texts, such as the Hindi Ramcharitmanas, believe their verses have the power of mantra as well. Some of the more powerful mantras consist of a single syllable, the most popular of which is “om.”
REFERENCE: Religion Stylebook