The Collaborative International Dictionary of English v.0.48:

Anagram \An"a*gram\ ([a^]n"[.a]*gr[a^]m), n. [F. anagramme, LL.
   anagramma, fr. Gr. 'ana` back, again + gra`fein to write. See
   Graphic.]
   Literally, the letters of a word read backwards, but in its
   usual wider sense, the change of one word or phrase into
   another by the transposition of its letters. Thus Galenus
   becomes angelus; William Noy (attorney-general to Charles I.,
   and a laborious man) may be turned into I moyl in law.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Anagram \An"a*gram\, v. t.
   To anagrammatize.
   [1913 Webster]

         Some of these anagramed his name, Benlowes, into
         Benevolus.                               --Warburton.
   [1913 Webster] Anagrammatic

WordNet (r) 3.0 (2006):

anagram
    n 1: a word or phrase spelled by rearranging the letters of
         another word or phrase
    v 1: read letters out of order to discover a hidden meaning
         [syn: anagram, anagrammatize, anagrammatise]