Mantra
Mantra (Sanskrit, "instrument of thought") is a sacred sound, syllable or repeated phrase used in Hinduism and Buddhism for meditation, prayer or invocation. The most famous: Om (universal vibration), Om mani padme hum (Tibetan Buddhist), Om namah Shivaya (Shaivite).
Functions
Sound resonance for concentration, mental purification (japa = repetition), connection with deity. Modern Mindfulness and Transcendental Meditation (Maharishi Mahesh Yogi, 1950s-1960s) popularized the use in the West.