Comprehensive resource for understanding and mastering English idioms
The idiom "greenhorn" refers to someone who is new or inexperienced, particularly when it comes to a certain activity or situation. It can also refer to someone who is naive or gullible.
The idiom "greenhorn" originated in the early 20th century and is believed to have come from the practice of branding cattle with green paint. New or inexperienced cowboys were often marked with green paint so that they could be easily identified and kept separate from the experienced ones. Over time, the term "greenhorn" came to refer to anyone who was new or inexperienced in general.