Wordnet 3.0
NOUN (1)
1. 
 (Islam) a legal opinion or ruling issued by an Islamic scholar; 
- Example: "bin Laden issued three fatwahs calling upon Muslims to take up arms against the United States"
The Collaborative International Dictionary of English v.0.48:
fatwa \fat"wa\, fatwah \fat"wah\, n.
   Same as fetwah.
   [PJC]
The Collaborative International Dictionary of English v.0.48:
Fetwah \Fet"wah\, n. [Ar.]
   A written decision of a Turkish mufti some point of law; also
   applied to opinions by certain other Islamic religious
   authorities on points of Islamic law, such as in Iran. [Also
   spelled fatwah and fatwa.] --Whitworth.
   [1913 Webster +PJC]
WordNet (r) 3.0 (2006):
fatwah
    n 1: (Islam) a legal opinion or ruling issued by an Islamic
         scholar; "bin Laden issued three fatwahs calling upon
         Muslims to take up arms against the United States"