Substantiv
rookie [pl. rookies]
freshman [pl. freshmen]
beginner [pl. beginners]
novice [pl. novices]
apprentice [pl. apprentices]
neophyte [pl. neophytes]
tyro [pl. tyros]
initiator [pl. initiators]
tenderfoot [pl. tenderfeet / tenderfoots]
initializer [pl. initializers]
founder [pl. founders]