Definition - What does Shanti mean?
Shanti is a Sanskrit term meaning "peace." In both Hindu and Buddhist practice, yogis chant shanti three times in order to promote peace in body, mind and spirit, such as in the mantra, Om Shanti Shanti Shanti. This mantra may also be used to close a Hindu or Buddhist worship service as a blessing of peace over the attendants.
Yogapedia explains Shanti
Shanti specifically refers to the state of inner peace. It is believed that when the chant is recited in meditation, it helps increase inner peace in the life of the reciter. Many yogis have the goal of reaching inner peace as central to their practice, and may wish to include the shanti chant into their meditation to cultivate more inner peace.
Chanting Sanskrit mantras is very effective for one's consciousness. It also stimulates the chakras, providing a calming, cleansing and energizing effect. In addition to chanting a mantra that invokes peace in order to reach inner peace, the mind also must let go of things in life, such as dissatisfaction and animosity.