The Collaborative International Dictionary of English v.0.48:

Openwork \O"pen*work`\, n.
   1. Anything so constructed or manufactured (in needlework,
      carpentry, metal work, etc.) as to show openings through
      its substance; work that is perforated or pierced.
      [1913 Webster]

   2. (Mining) A quarry; an open cut. --Raymond.
      [1913 Webster]

WordNet (r) 3.0 (2006):

openwork
    n 1: ornamental work (such as embroidery or latticework) having
         a pattern of openings