Definition of "shanti"

Datta. Dayadhvam. Damyata. / Shantih shantih shantih […] Shantih. Repeated as here, a formal ending to a Upanishad. "The Peace which passeth understanding" is a feeble translation of the content of this word.

1922 October, T[homas] S[tearns] Eliot, “Part V. What the Thunder Said.”, in The Waste Land, 1st book edition, New York, N.Y.: Boni and Liveright, published December 1922, pages 49 and 64