openworko‧pen‧work /ˈəʊpənˌwɜːk $ ˈoʊpənˌwɜːrk/ adjective [only before noun] 
an openwork object has a pattern of open spaces between the material that it is made from: 
an openwork stone screen
an openwork object has a pattern of open spaces between the material that it is made from: an openwork stone screen