The DICT Development Group

  birthday suit
      n 1: informal terms for nakedness; "in the raw"; "in the
           altogether"; "in his birthday suit" [syn: raw,
           altogether, birthday suit]

  19 Moby Thesaurus words for "birthday suit":
     bareness, decollete, ecdysiast, gymnosophist, gymnosophy,
     nakedness, naturism, naturist, not a stitch, nudism, nudist,
     nudity, state of nature, stripper, stripteaser, the altogether,
     the nude, the raw, toplessness