Answer:
Armistice: truce, ceasefire, suspension of hostilities, cessation of hostilities, peace, break, respite, lull, moratorium, treaty, peace treaty, and letup.
Trench: ditch, channel, trough, excavation, pit, furrow, rut, conduit, cut, drain, , waterway, watercourse, earthwork, entrenchment, moat, fosse, and sap.
Propaganda: information, promotion, advertising, advertisement, publicity, advocacy, spin, newspeak, agitprop, disinformation, counter-information, brainwashing, indoctrination, the big lie, info, hype, and plugging.