Pas ‧ schen ‧ daele /ˈpæʃ ə ndeɪl/ BrE AmE
an important battle during World War I in 1917, in northwest Belgium, in which over 200,000 British soldiers were killed. It is remembered especially for the ↑ mud (=soft wet earth) , which made the terrible conditions in which the soldiers lived and fought even worse.