[1] : The Collaborative International Dictionary of English v.0.48

undress \undress"\, v. t. 1st pref. un- + dress.
   1913 webster
   1. to divest of clothes; to strip.
      1913 webster

   2. to divest of ornaments to disrobe.
      1913 webster

   3. med. to take the dressing, or covering, from; as, to
      undress a wound.
      1913 webster

[2] : The Collaborative International Dictionary of English v.0.48

undress \un"dress\, n.
   1. a loose, negligent dress; ordinary dress, as distinguished
      from full dress.
      1913 webster

   2. mil.  naval an authorized habitual dress of officers
      and soldiers, but not full-dress uniform.
      1913 webster

   undress parade mil., a substitute for dress parade,
      allowed in bad weather, the companies forming without
      arms, and the ceremony being shortened.
      1913 webster
see also:
undress parade 

[3] : WordNet (r) 2.0

undress
     n : partial or complete nakedness; "a state of undress"
     v 1: get undressed; "please don't undress in front of
          everybody"; "she strips in front of strangers every
          night for a living" syn: discase, uncase, unclothe,
           strip, strip down, disrobe, peel ant: dress,
           dress
     2: remove someone's or one's own clothes; "the nurse quickly
        undressed the accident victim"; "she divested herself of
        her outdoor clothes"; "he disinvested himself of his
        garments" syn: strip, divest, disinvest
see also:
discase uncase unclothe strip strip down disrobe 
peel dress divest disinvest 

[4] : Moby Thesaurus II by Grady Ward, 1.0

36 moby thesaurus words for "undress":
   baldness, bareness, beauty unadorned, casual clothes, debunk,
   denude, disarray, discover, dishabille, dismantle, disrobe,
   do a strip-tease, nakedness, neglige, negligee, nudity, show up,
   something comfortable, sport clothes, strip, unadulteration,
   unarray, uncase, uncloak, unclothe, uncomplexity,
   uncomplicatedness, uncomplication, undrape, unembellishment,
   unmask, unornamentation, unshroud, unsophistication, wrap,
   wrapper

Undress >> U Words
Undress, definition of term: Undress
undress_pag1.html