Om (or Aum) is a sacred syllable in, both, Hinduism and Buddhism. The syllable is sometimes referred to as, "the Udgitha". The Chandogya Upanishad (1.1.1-10) states, "The udgitha is the best of all essences, the highest, deserving the highest place, the eighth." It has been argued that Om can be translated, into English, as "yes". Notes the Chandogya Upanishad, "That syllable, is a syllable of permission; for, whenever we permit anything, we say Om."
Om is a river in Russia; it is ~724km long.