Webster's Revised Unabridged Dictionary · 1913

Tetragrammaton

Tetragrammaton , noun

[New Latin, from Greek {not transcribed}; te`tra- (see Tetra-) + {not transcribed} 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.