IDIOMS

in the altogether

(idiomatic, euphemistic) Naked.

Example: 1930 Aug. 4, "Prix de Rome," Time:
  Hearing that his wife was posing in the altogether for the great Spanish satirist, the Duke of Alba swore that he would paint Goya's picture in Goya's blood.
2004 Nov. 25, David Carr, "When a TV Talking Head Becomes a Talking Body," New York Times (retrieved 16 Sep 2008):
  Last week, a Cleveland news anchor, Sharon Reed, was caught on camera stripping nude and joining a gaggle of other people in the altogether.