The Collaborative International Dictionary of English v.0.48:

Jinnee \Jin"nee\, Jinni \Jin"ni\(j[i^]n"n[=e]), n.; pl. Jinn
   (j[i^]n). [Ar.] (Arabian & Mohammedan Myth.)
   A genius or demon; one of the fabled genii, good and evil
   spirits, supposed to be the children of fire, and to have the
   power of assuming various forms. [Written also djinnee,
   genie, etc.]

   Syn: jinn; jin; djinn.
        [1913 Webster]

   Note: Jinn is also used as sing., with pl. jinns.
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

djinnee \djin"nee\ djinni \djin"ni\, djinny
\djin"ny\(j[i^]n"n[=e]), n.; pl. djinn (j[i^]n) or djinns
   (j[i^]nz).
   A spirit believed by Muslims to inhabit the earth and
   influence mankind by appearing in the form of humans or
   animals. Same as djinni and Jinnee. See Jinnee, Jinn.

   Syn: genie, jinn, jinni, jinnee, djinn, djinni.
        [1913 Webster + WordNet 1.5]