Literally: One sent forth; a messenger. Specifically: One of the twelve disciples of Christ, specially chosen as his companions and witnesses, and sent forth to preach the gospel.
- One of a group made up especially of the 12 disciples chosen by Jesus to preach the gospel.
- A missionary of the early Christian Church.
- A leader of the first Christian mission to a country or region.
- One of the 12 members of the administrative council in the Mormon Church.
- One who pioneers an important reform movement, cause, or belief: an apostle of conservation.
- A passionate adherent; a strong supporter.