neophyte (n.)

"new convert," 1550s, from Church Latin neophytus, from Greek neophytos "a new convert," noun use of adjective meaning "newly initiated, newly converted," literally "newly planted," from neos "new" (see new) + phytos "grown; planted," verbal adjective of phyein "to bring forth, make grow," from PIE root *bheue- "to be, exist, grow." Church sense is from I Timothy iii.6. Rare before 19c. General sense of "one who is new to any subject" is first recorded 1590s.