DuckCorp Dico

Found one definition

1.                 From WordNet (r) 3.0 (2006):
                   
   
   
                   
                     
   in line
       adv 1: one behind another in a line or queue; "they waited in
              line for the tickets"
       adj 1: being next in a line of succession; "he was in line for
              the presidency"
       2: awaiting something; especially something due; "people were in
          line at the checkout counter"; "she was in line for
          promotion"