catechumen

noun1

1. •
   A student of Christian doctrine who studies it for the purpose of adopting it: either a convert to Christianity under instruction before baptism or a young or recent Christian preparing for confirmation.

   • Here in this room an old man had killed and boiled a catechumen, had committed sodomy with a rat, had discussed a rodent nunhood with V., a future saint – depending which story you listened to. — 1963