The Collaborative International Dictionary of English v.0.48:

Tetramorph \Tet"ra*morph\, n. [Tetra- + Gr. morfh` form, figure:
   cf. Gr. ? fourfold.] (Christian Art)
   The union of the four attributes of the Evangelists in one
   figure, which is represented as winged, and standing on
   winged fiery wheels, the wings being covered with eyes. The
   representations of it are evidently suggested by the vision
   of Ezekiel (ch. i.)
   [1913 Webster]