The Collaborative International Dictionary of English v.0.48:

Mufti \Muf"ti\, n.; pl. Muftis. [Ar. mufti.]
   1. An official expounder of Mohammedan law.
      [1913 Webster]

   2. One of the chief legal advisers to the Sultan of the
      Ottoman Empire.
      [PJC]

The Collaborative International Dictionary of English v.0.48:

mufti \muf"ti\, n.
   Ordinary civilian dress when worn by persons who serve in a
   uniformed service, such as the military or police. It
   originally was used in reference to British naval or military
   officers, and originated with the British service in India.
   [Colloq. Eng.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

mufti
    n 1: a jurist who interprets Muslim religious law
    2: civilian dress worn by a person who is entitled to wear a
       military uniform