Johnny-Come-Lately

Etymology:

• In 19th century, a newly arrived sailor was called “Johnny Newcomer” by the British, because he was amateur and new in the ship. Later the American sailors changed this saying a bit and it was made “Johnny-come-lately” to refer to a person who was newly recruited in navy and had just come lately. Today the phrase “Johnny-come-lately” can be used for any person who is new in any field, or is inexperienced in any organization, group, school etc.