The Collaborative International Dictionary of English v.0.48:

Heliogravure \He`li*o*grav"ure\, n. [F. h['e]liogravure.]
   1. The process of photographic engraving.
      [1913 Webster]

   2. A plate or picture made by the process of heliogravure.
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

heliogravure
    n 1: an intaglio print produced by gravure [syn: gravure,
         photogravure, heliogravure]