"new convert," 1550s, from Ecclesiastical 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 "cause to grow, beget, plant" (see physic). Church sense is from I Tim. iii:6. Rare before 19c. General sense of "one who is new to any subject" is first recorded 1590s.