The Collaborative International Dictionary of English v.0.48:

Scrimmage \Scrim"mage\ (?; 48), n. [A corruption of skirmish.
   "Sore scrymmishe." --Ld. Berners.] [Written also
   scrummage.]
   1. Formerly, a skirmish; now, a general row or confused fight
      or struggle.
      [1913 Webster]

   2. (Football) The struggle in the rush lines after the ball
      is put in play.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Scrummage \Scrum"mage\ (?; 43), n.
   See Scrimmage.
   [1913 Webster]

WordNet (r) 3.0 (2006):

scrummage
    n 1: (rugby) the method of beginning play in which the forwards
         of each team crouch side by side with locked arms; play
         starts when the ball is thrown in between them and the two
         sides compete for possession [syn: scrum, scrummage]