A freshman is a student in her first year of high school or college. Being a college freshman can be a little overwhelming — it's a huge change in most people's lives.
Sometimes a freshman is called a "first-year student," a term that isn't so gender-specific. However, you can also use the word freshman for a a boy or a girl. Sometimes, rather than school, a freshman is new at something else: in the US Senate, first-timers are frequently called "freshman senators." The word combines the "inexperienced" sense of fresh with man, or "person."