1an important assignment given to a person or group of people, typically involving travel abroad:a fact-finding mission to the Czech Republic
[treated as singular or plural] a group of people sent on a mission:by then, the mission had journeyed over 3,500 miles
an organization or institution involved in a long-term assignment abroad:the head of the West German mission
an operation carried out by military aircraft:a reconnaissance mission
an expedition into space:NASA has approved a mission to investigate the atmosphere of Mars
2the vocation or calling of a religious organization, especially a Christian one, to go out into the world and spread its faith:the Christian mission [mass noun]:Gandhi’s attitude to mission and conversion
a building or group of buildings used by a Christian mission:a tour of the missions on the California coast
3a strongly felt aim, ambition, or calling:his main mission in life has been to cut unemployment
