Definitions for "Jehovah"
A Scripture name of the Supreme Being, by which he was revealed to the Jews as their covenant God or Sovereign of the theocracy; the "ineffable name" of the Supreme Being, which was not pronounced by the Jews.
the Hebrew name of God in the Old Testament.
A name for God invented by a Catholic monk named Raymundus in AD 1270. He added the vowels of "Adonai" (Hebrew for "Lord") to YHWH, the Hebrew name for God (meaning "I AM"). Jehovah's Witnesses wrongly claim that Jehovah is the only true and correct name of God - a ridiculous claim considering the origin of the name. (Take a look at where the Jehovah's Witnesses' name came from.)