[count] 1 a : a task or job that someone is given to do
▪ Our mission was to recover the stolen plans. ▪ He was sent on a fact-finding mission. = He was sent on a mission to gather information. ▪ By patient negotiation she succeeded in her mission of averting a strike. ▪ go on a rescue mission [=go somewhere to rescue someone] ▪ The volunteers were on a mission of mercy to help victims of the disaster. [=the volunteers were sent to help the victims of the disaster] ▪ a mercy mission
b : a specific military or naval task
▪ a reconnaissance mission ▪ a peacekeeping mission ▪ a combat/training mission
c : a flight by an aircraft or spacecraft to perform a specific task
▪ a bombing mission ▪ a manned space mission ▪ a shuttle mission ▪ a mission to the moon — see also mission control 2 : a task that you consider to be a very important duty
▪ His mission is to help poor children. = He has made it his mission in life to help poor children. = He's a man with a mission: to help poor children. ▪ She's on a mission to locate her lost sister. [=she is very determined to find her lost sister] 3 : a group of people sent to a foreign country for a specific reason (such as to have discussions or to provide training or assistance)
▪ a member of a trade mission 4 a : a group of people who are sent to a foreign country to do religious work : a group of missionaries
▪ a Catholic mission
b : a place or building where such work is done
▪ touring a Spanish mission in California ▪ a mission church