IPA: /ˈmɪʃənər/
KK: /ˈmɪʃənər/
A person who is sent to a foreign country to promote Christianity or to help others, often through education or social work.
The missioner traveled to Africa to provide education and support to local communities.
Missioner → It is formed from "mission" (from Latin "missio", meaning sending) and "-er" (meaning a person who). A missioner is a person who is sent on a mission, often for religious or charitable purposes.
Think of someone who is 'sent' ('missio') to accomplish a specific task — that's what a missioner does.