Redrum
From Super-wiki
Redrum
The word murder spelled backwards. It was first used in "The Shining" by Stephen King and then in both the film and the miniseries that were made based on the book.
– Pad of Definitions (2.07 The Usual Suspects), Official Website
2.07 The Usual Suspects
Sam: Anagram, maybe?
And
Dean: I think it's an anagram.
Kraus: A what?
Dean: An anagram. Same letters, different words.
And
Dean: You know, it's, uh, maybe word fragments... other times, it's anagrams.