adonist

from The Century Dictionary.

• noun One who maintained that the vowel-points ordinarily written under the consonants of the Hebrew word JHVH (pronounced since the sixteenth century, except among the Jews, Jehovah) are not the natural points belonging to that word, but are vowel-points belonging to the words Adonai and Elohim; these words are substituted in reading by the Jews for the name JHVH, a name which they are forbidden to utter, and the true pronunciation of which is lost. Those persons who held the opposite view were termed Jehovists.

from the GNU version of the Collaborative International Dictionary of English.

• noun One who maintains that points of the Hebrew word translated “Jehovah” are really the vowel points of the word “Adonai.” See jehovist.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun One who maintains that the vowel points of the Tetragrammaton translated "Jehovah" are the vowel points that belong to the word Adonai.