Source : Webster's Revised Unabridged Dictionary (1913)

IHVH \IHVH\ [Written also {JHVH}, {YHVH}.]
   A transliteration of the four constants forming the Hebrew
   tetragrammaton or ``incommunicable name'' of the Supreme
   Being, which in latter Jewish tradition is not pronounced
   save with the vowels of adonai or elohim, so that the true
   pronunciation is lost.

   Note: Numerous attempts have been made to represent the
         supposed original form of the word, as Jahaveh, Jahvaj,
         Jahve, Jahveh, Yahve, Yahveh, Yahwe, Yahweh, etc.