Source : Webster's Revised Unabridged Dictionary (1913)

Freshman \Fresh"man\, n.; pl. {Freshmen}.
   novice; one in the rudiments of knowledge; especially, a
   student during his fist year in a college or university.

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

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

Source : WordNet®

freshman class
     n : the first class in college or high school