mufti

noun pl. -·tis

1. in Muslim countries, an interpreter or expounder of religious law
2. ordinary clothes, esp. when worn by one who normally wears, or has long worn, a military or other uniform

Etymology: Ar, one who gives a decisive response < āftā, to judge; muftisense ? in allusion to the Muslimlike dressing gown and tasseled cap worn by an officer off duty in the early 19th c.