The Collaborative International Dictionary of English v.0.48:

Refresher \Re*fresh"er\ (-?r), n.
   1. One who, or that which, refreshes.
      [1913 Webster]

   2. (Law) An extra fee paid to counsel in a case that has been
      adjourned from one term to another, or that is unusually
      protracted.
      [1913 Webster]

            Ten guineas a day is the highest refresher which a
            counsel can charge.                   --London
                                                  Truth.
      [1913 Webster]

WordNet (r) 3.0 (2006):

refresher
    n 1: a fee (in addition to that marked on the brief) paid to
         counsel in a case that lasts more than one day
    2: a drink that refreshes; "he stopped at the bar for a quick
       refresher"
    3: a course that reviews and updates a topic for those who have
       not kept abreast of developments [syn: refresher course,
       refresher]