a word, phrase, or sentence formed from another by rearranging its letters

Angel is an anagram of glean.

anagrams, ( used with a singular verb ) a game in which the players build words by transposing and, often, adding letters.

to form (the letters of a text) into a secret message by rearranging them.

to rearrange (the letters of a text) so as to discover a secret message.

noun

cipher , game , logograph , puzzle