Source : Webster's Revised Unabridged Dictionary (1913)

Roster \Ros"ter\, n. [Perhaps a corruption of register; or cf.
   roll.] (Mil.)
   A register or roll showing the order in which officers,
   enlisted men, companies, or regiments are called on to serve.

Source : WordNet®

roster
     n : a list of names; "his name was struck off the rolls" [syn: {roll}]