DuckCorp Dico

Found one definition

1.                 From WordNet (r) 3.0 (2006):
                   
   
   
                   
                     
   senior
       adj 1: older; higher in rank; longer in length of tenure or
              service; "senior officer" [ant: junior]
       2: used of the fourth and final year in United States high
          school or college; "the senior prom" [syn: senior(a),
          fourth-year]
       3: advanced in years; (`aged' is pronounced as two syllables);
          "aged members of the society"; "elderly residents could
          remember the construction of the first skyscraper"; "senior
          citizen" [syn: aged, elderly, older, senior]
       n 1: an undergraduate student during the year preceding
            graduation
       2: a person who is older than you are [syn: elder, senior]