Khurafat [Khurāfāta] is an Urdu word which means a mischief or an outrageous incident. The word is more used for a mischief or a prank that is actually not yet carried out, though the word can be equally well used for a prank that is carried out.
An example would be, "Kya khurafaat chal rahi hai tere dimaag mein?", i.e. "what mischief is going about in your mind?"
Khurafati is someone who keeps on thinking of such mischieves and pranks. The word is used as an adjective for persons as well as mind. As in, 'khurafati dimaag' would mean a mischievous mind.