'Tetragrammaton' definitions:

Definition of 'Tetragrammaton'

(from WordNet)
noun
Four Hebrew letters usually transliterated as YHWH (Yahweh) or JHVH (Jehovah) signifying the Hebrew name for God which the Jews regarded as too holy to pronounce

Definition of 'Tetragrammaton'

From: GCIDE
  • Tetragrammaton \Tet`ra*gram"ma*ton\, n. [NL., fr. Gr. ?; te`tra- (see Tetra-) + ? a letter.] The mystic number four, which was often symbolized to represent the Deity, whose name was expressed by four letters among some ancient nations; as, the Hebrew JeHoVaH, Greek qeo`s, Latin deus, etc. [1913 Webster]