Wordnet 3.0
NOUN (1)
1. 
 battle in World War I (1917); 
 an Allied offensive which eventually failed because tanks bogged down in the waterlogged soil of Flanders; 
 Germans introduced mustard gas which interfered with the Allied artillery; 
[syn: Ypres, battle of Ypres, third battle of Ypres]
WordNet (r) 3.0 (2006):
third battle of Ypres
    n 1: battle in World War I (1917); an Allied offensive which
         eventually failed because tanks bogged down in the
         waterlogged soil of Flanders; Germans introduced mustard
         gas which interfered with the Allied artillery [syn:
         Ypres, battle of Ypres, third battle of Ypres]