Search Result for "antigram": 
Wordnet 3.0

NOUN (1)

1. an anagram that means the opposite of the original word or phrase;
- Example: "`restful' is the antigram of `fluster'"



WordNet (r) 3.0 (2006):

antigram
    n 1: an anagram that means the opposite of the original word or
         phrase; "`restful' is the antigram of `fluster'"