A freshman, fresher, first year, or colloquially frosh, is a person in the first year at an educational institution, usually a secondary school or at the college and university level, but also in other forms of post-secondary educational institutions. Freshman is commonly used as a US English idiomatic term to describe a beginner or novice, someone who is naive, a first effort, instance, or a student in the first year of study (generally referring to high school or university study).

Source: Wikipedia