A beginner; a person who is new to a subject, skill, or belief.
A novice (recent convert); a new convert or proselyte; a new monk.
A name given by the early Christians, and still given by the Roman Catholics, to those who have recently embraced the Christian faith, and been admitted to baptism, especially those converts from heathenism or Judaism.
A plant species recently introduced to an area (in contrast to archaeophyte, a long-established introduced species).