The Collaborative International Dictionary of English v.0.48:

getup \get"up\, get-up \get"-up\, n.
   1. General composition or structure; manner in which the
      parts of a thing are combined; arrangement; format;
      make-up; style of dress, etc. [Colloq.] --H. Kingsley.
      [1913 Webster]

   2. Specifically: A set of clothing (with accessories); as,
      what are you doing in that getup?; -- often used with
      implied disapproval or scorn. [informal] [WordNet sense 1]

   Syn: outfit, rig.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

getup
    n 1: a set of clothing (with accessories); "his getup was
         exceedingly elegant" [syn: outfit, getup, rig,
         turnout]