The Collaborative International Dictionary of English v.0.48:

Jehovist \Je*ho"vist\, n.
   1. One who maintains that the vowel points of the word
      Jehovah, in Hebrew, are the proper vowels of that word; --
      opposed to adonist.
      [1913 Webster]

   2. The writer of the passages of the Old Testament,
      especially those of the Pentateuch, in which the Supreme
      Being is styled Jehovah. See Elohist.
      [1913 Webster]

            The characteristic manner of the Jehovist differs
            from that of his predecessor [the Elohist]. He is
            fuller and freer in his descriptions; more
            reflective in his assignment of motives and causes;
            more artificial in mode of narration. --S. Davidson.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Yahwist \Yah"wist\, n. Also Jahvist \Jah"vist\, Jahwist
\Jah"wist\, older Jehovist \Je*ho"vist\
   The author of the passages of the Old Testament, esp. those
   of the Hexateuch, in which God is styled Yahweh, or Jehovah;
   the author of the Yahwistic, or Jehovistic, Prophetic
   Document (J); also, the document itself.
   [Webster 1913 Suppl.]