Battle of the Marne batt·leoft·he·marne uncommon noun 1. a World War I battle in northwestern France where the Allies defeated the Germans in 1918 SynonymsBattle of the MarneBelleau WoodChateau-ThierryMarne River Related words Broader terms pitched battle Parts World War I WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.