missionmis·sion /ˈmɪʃən/ noun [countableC] 1an important job that someone is given to do
Her mission was to improve staff morale and output.
2the aim of a company or organization
Our mission is to provide quality long-term care to the maximum number of patients.
3a trip that a group of people are sent on, for example in order to collect information
He has just been on a fact-finding mission to China.
4a group of people who are sent by their government or an important organization to another country to collect information, have discussions etc → trade mission
The UN has sent a mission to the area.