YHWH (LORD) & "Jehovah"
(adapted from Bernard W. Anderson's Understanding the Old Testament [Upper Saddle River: Prentice Hall, 1998] 56–57.)
 
The personal divine name YHWH, cryptically referred to in Exodus 3.13, has an interesting history. In the biblical period the Hebrew language was written only with consonants. Vowels were not added until the Common Era (C.E.), when Hebrew was no longer a living language. On the basis of the Greek texts, which use both vowels and consonants, scholars believe that the original pronunciation was “Yah-weh.” Notice the shortened form of the divine name in the exclamation, “Halleluyah” (from the Hebrew hallelu yah, “Praise Yah”).

Because of its holy character, the name Yahweh was withdrawn from ordinary speech during the period of the Second Temple  (about 500 B.C.E. and later). Another Hebrew word
a title, not a personal namewas substituted: Adonai, or “(The) Lord,” a name still used in synagogues. Scholars who translated the Hebrew Bible into Greek (the Septuagint) in the third century B.C.E. adopted this synagogue convention and rendered YHWH as (ho) kurios, “(the) Lord.” From this Greek translation the practice was carried over into the New Testament.

The word “Jehovah” is an artificial form that arose from the combination of the consonants YHWH with the vowels of Adonai, written under or over the Hebrew consonants to indicate pronunciation. This hybrid form is often attributed to Peter Galatin, confessor of Pope Leo X, in a publication dated 1518 C.E., but in actuality it can be traced back to a work by
Raymond Martin in 1270.

Jewish reverence for the divine name has influenced numerous modern translations, including the Septuagint. These translations follow the ancient synagogue practice and substitute Adonai (translated “El Señor” in Spanish, “Der Herr” in German, “The Lord” in English, and so on). The 
New Jerusalem Bible uses the presumed original form, “Yahweh."