A greenhorn is a person who is new and inexperienced. It can also refer to someone who is naive or immature. The term has been around for centuries, and no one is certain how it originated.
Immigrants are considered greenhorns because they are new to a country, but anyone who is new to any culture or society can be one. A woman whose spent all her life in New York City would find everything strange and new if she moved to a small town or a farm, and vice versa. The same situation would occur for someone moving from the suburbs of Melbourne, Australia to the Australian Outback. Even though they are in the same country, the cultures are different.
People do not have to move to become a novice. Anyone beginning a new job is untrained and inexperienced, a greenhorn at their new position. A child who was homeschooled for many years would be one if he began attending public school because he wouldn’t know the routines and expectations.
Since newcomers are often unsure of themselves and unfamiliar with the people they meet, they can be easily deceived. The term greenhorn can therefore also refer to someone who is especially naive or gullible, whether or not they are new. Many people shun this term for anyone because of this definition.
Another negative definition is unsophisticated or immature. Newcomers to a nation, culture, or workplace rarely know the unwritten expectations of that culture, and thus they unknowingly break them. Anyone who doesn’t act properly can be called a greenhorn.
One likely origin of the term greenhorn comes from the fifteenth century. The adjective “green” has been used as a synonym for “young” for centuries, in reference to young plants and fruit. A green horn was a young ox, whose horns had not fully formed. By 1650, freshly recruited soldiers were being called greenhorns, presumably as a comparison to young oxen.
The term could also have originated with a certain type of jewelry popular in the 1600s. This jewelry, which looked like a cameo, was made of horn, heated, pressed into a mold, and placed in a silver frame. If the horn got overheated, it would turn green. Mistakes are most often made by those who are new to the craft, so new apprentices would be called greenhorns because they mistakenly turned the horn green.