What is the X in X-mas?
1530, Tyndale's erroneous transliteration of Hebrew Tetragramaton YHWH using vowel points of Adhonai "my lord" (see Yahweh). Used for YHWH (the full name being too sacred for utterance) in four places in the Old Testament in the KJV where the usual translation lord would have been inconvenient; taken as the principal and personal name of God.
The vowel substitution was originally made by the Masoretes as a direction to substitute Adhonai for "the ineffable name." European students of Hebrew took this literally, which yielded Latin JeHoVa (first attested in writings of Galatinus, confessor to Leo X, 1516). Jehovah's Witnesses "member of Watchtower Bible and Tract Society" first attested 1933; the organization founded c.1879 by Charles Taze Russell (1852-1916); the name from Isa. xliii:10.
Another name for God; an approximation of the holiest name of God in Hebrew (the name was held so sacred that it was never written or spoken, and scholars are not sure exactly how it should be pronounced). It means “I am that I am,” or “I am the one who is.” In the incident of the burning bush in the Book of Exodus, God, speaking out of the bush, tells Moses that this is his name.
the special and significant name (not merely an appellative title such as Lord [adonai]) by which God revealed himself to the ancient Hebrews (Ex. 6:2, 3). This name, the Tetragrammaton of the Greeks, was held by the later Jews to be so sacred that it was never pronounced except by the high priest on the great Day of Atonement, when he entered into the most holy place. Whenever this name occurred in the sacred books they pronounced it, as they still do, "Adonai" (i.e., Lord), thus using another word in its stead. The Massorets gave to it the vowel-points appropriate to this word. This Jewish practice was founded on a false interpretation of Lev. 24:16. The meaning of the word appears from Ex. 3:14 to be "the unchanging, eternal, self-existent God," the "I am that I am," a convenant-keeping God. (Comp. Mal. 3:6; Hos. 12:5; Rev. 1:4, 8.) The Hebrew name "Jehovah" is generally translated in the Authorized Version (and the Revised Version has not departed from this rule) by the word LORD printed in small capitals, to distinguish it from the rendering of the Hebrew _Adonai_ and the Greek _Kurios_, which are also rendered Lord, but printed in the usual type. The Hebrew word is translated "Jehovah" only in Ex. 6:3; Ps. 83:18; Isa. 12:2; 26:4, and in the compound names mentioned below. It is worthy of notice that this name is never used in the LXX., the Samaritan Pentateuch, the Apocrypha, or in the New Testament. It is found, however, on the "Moabite stone" (q.v.), and consequently it must have been in the days of Mesba so commonly pronounced by the Hebrews as to be familiar to their heathen neighbours.
the God of the Israelites, his name being revealed to Moses as four Hebrew consonants (YHWH) called the tetragrammaton. After the Exile (6th century BC), and especially from the 3rd century BC on, Jews ceased to use the name Yahweh for two reasons. As Judaism became a universal religion through its proselytizing in the Greco-Roman world, the more common noun Elohim, meaning "god," tended to replace Yahweh to demonstrate the universal sovereignty of Israel's God over all others. At the same time, the divine name was increasingly regarded as too sacred to be uttered; it was thus replaced vocally in the synagogue ritual by the Hebrew word Adonai ("My Lord"), which was translated as Kyrios ("Lord") in the Septuagint, the Greek version of the Old Testament.