From Longman Dictionary of Contemporary Englishentrenchmenten‧trench‧ment /ɪnˈtrentʃmənt/ noun 1 [uncountable]CHANGE YOUR MIND when an attitude, belief etc becomes firmly established2 [countable]PMD a system of trenches (=long deep holes) dug by soldiers for defence or protection
Examples from the Corpus
entrenchment• As the banks were rather steep the defenders spent several days cutting entrenchments and embrasures in expectation of battle.• Thousands of Union men were set to digging entrenchments and preparing emplacements for siege guns.• The foot were also responsible for entrenchments and for engineering works associated with sieges.• The dogmatic resistance to entrenchment would raise its arid and pedantic head. 