peace corps volunteer:
(plural: ‘peace corps volunteers‘; for the right pronunciation of ‘peace corps’, please click here & for ‘volunteer’, please click here)

peace corps volunteers at a camp
a person/an American who is trained and sent to other countries for the “peace corps” of the USA, (to keep peace between fights forces, especially internal fights)
e.g.
John F. Kennedy, the former president of the US, is the creator of the peace corps.
Peace Corps volunteers are mostly young Americans who are willing to work for peace and prosperity in some developing countries, often working under very harsh conditions in those countries.

a peace corps volunteer with local children in Africa
