The Collaborative International Dictionary of English v.0.48:

Filigrain \Fil"i*grain\, Filigrane \Fil"i*grane\, n. [Sp.
   filigrana (cf. It. filigrana, E. filigrane), fr. L. filuma
   thread + granum grain. See File a row, and Grain, and cf.
   Filigree.]
   Filigree. [Archaic]
   [1913 Webster]

         With her head . . . touches the crown of filigrane.
                                                  --Longfellow.
   [1913 Webster]