The Collaborative International Dictionary of English v.0.48:

Freshman \Fresh"man\, n.; pl. Freshmen.
   A novice; one in the rudiments of knowledge; especially, a
   student during his first year in a high school, college, or
   university.

   Syn: frosh.
        [1913 Webster]

              He drank his glass and cracked his joke,
              And freshmen wondered as he spoke.  --Goldsmith.
        [1913 Webster]

   Freshman class, the lowest of the four classes in an
      American college. [ U. S.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

freshman
    adj 1: used of a person in the first year of an experience
           (especially in United States high school or college); "a
           freshman senator"; "freshman year in high school or
           college" [syn: freshman, first-year]
    n 1: a first-year undergraduate [syn: freshman, fresher]
    2: any new participant in some activity [syn: newcomer,
       fledgling, fledgeling, starter, neophyte, freshman,
       newbie, entrant]