| ceasefire | an arrangement in which countries or groups of people that are fighting each other agree to stop fighting |
| celerity | swiftness in acting or moving; speed |
| censor | to officially examine letters of the media and cut out any information that is regarded as secret |
| cipher | a secret system of writing used to send encrypted messages |
| civil war | a war or conflict fought between 2 or more different groups of people who live in the same country |
| civilian | describes a person who is not a member of the armed forces |
| coalition | an alliance between two or more nations, groups or political parties, especially for some temporary and specific reason |
| collectivism | the political belief that a country's industries and services should be owned and controlled by the state or by all the people in a country |
| collier | a ship designed to transport coal |
| colony | a country that is controlled by a more powerful country |
| commandeer | officially take charge of a vehicle, vessel, building, supplies or equipment for a military purpose |
| commemorate | to remember an event or person through a special action or ceremony or a specially created object |
| commerce raiding | a form of naval warfare that disrupt logistics of the enemy on the open sea by attacking its merchant shipping |
| compensation | money or anything given as an equivalent to make amends for losses or damages |
| conscientious objector | someone who refuses to meet a community or political obligation, such as compulsory military service |
| conscription | when citizens are made to join their country's military force, such as the army |
| contingent | a group of military personnel serving on the same side or for the same cause |
| convalesce | to rest and recover health after an illness or operation |
| convoy | a group of ships with an escort of warships, or a group of vehicles travelling together with a military escort |
| cordite | a smokeless explosive substance used in bombs and guns |
| cot case | a person too ill to leave their bed |
| counterattack | a military attack in response to an attack |
| coup d'etat | overthrowing of an existing government illegally or by force |
| curfew | a law that people must stay home after a particular time at night, often during a war or civilian crisis |
| de-mining | the process of removing landmines |
| decoration | an official title or honour given to someone, usually in the form of a medal, as a reward for military bravery |
| degenerate | to become worse in some way |
| delegation | a small group of people sent to a place to have talks with other people as representatives of a larger group of people |
| demilitarise | to remove any military presence or function in an area |
| demobilise | to release troops from military service - demobilisation (noun) |
| deploy | to organise and position troops, weapons or resources ready for action - deployment (noun) |
| descent | a person's family background, especially their nationality or social status |
| deserter | someone who leaves their job in the armed forces without permission |
| destroyer | a small, heavily armed warship |
| detachment | a group of soldiers sent away from the main group to do a special job |
| dictator | a ruler who has complete power in a country, especially power which was obtained by force and is used unfairly |
| digger | an Australian or New Zealander, especially a soldier; often used as a term of address |
| diorama | a miniature three-dimensional scene with models of figures arranged against a background |
| dirigible | an airship, such as a zeppelin |
| disembark | to unload goods or passengers from a ship or aeroplane |
| dismount | to get down from a camel, horse, bicycle or armoured vehicle |
| dispatch | a message or report that is sent by army officers or government officials to their headquarters - also 'despatch' |
| displaced | persons who lack a home, through war, political exile, destruction of shelter, or lack of money |
| displaced person | someone who lost their home through war, political exile, destruction of shelter or lack of money |
| diversionary | describes an action to distract the enemy from the main point of attack |
| dogfighting | an aerial battle between opposing fighter planes |
| dominion | a nation that was part of the British Empire but had its own government e.g. Australia from 1901 to 1953 |
| dysentery | an infection of the intestine with bacteria or protozoa, characterised by severe diarrhoea |
| egalitarian | supporting the idea that all people are equal and should have the same rights and opportunities |
| embark | to load goods or passengers onto a ship or aeroplane |