From Longman Dictionary of Contemporary Englishtrench warfareˌtrench ˈwarfare noun [uncountable] PMa method of fighting in which soldiers from opposing armies are in trenches facing each other
Examples from the Corpus
trench warfare• Yet to continue trench warfare as before would be a mistake.• Lastly, trench warfare is a policy Mr Yeltsin has pursued with some success for much of the past 12 months.• The little-noticed trench warfare over Senate confirmation of presidential appointees is nothing new.• The musical evokes the courage and humour of the troops amidst the horror of trench warfare.• More years of trench warfare and carnage on the Western Front.were now almost unavoidable. 