1
general::
Phrase(s): the naked truth
the complete, unembellished truth. • Sorry to put it to you like this, but it’s the naked truth. • I can take it. Just tell me the naked truth.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Plain unadorned facts, without concealment or embellishment. For example, What I've told you is the naked truth. This expression supposedly alludes to a fable in which Truth and Falsehood went bathing, Falsehood then dressed in Truth's clothes, and Truth, refusing to take another's clothes, went naked. [Late 1500s]
American Heritage Idioms