Source : Webster's Revised Unabridged Dictionary (1913)

Sle \Sle\, v. t.
   To slay. [Obs.] --Chaucer.

Source : WordNet®

SLE
     n : an inflammatory disease of connective tissue with variable
         features including fever and weakness and fatigability
         and joint pains and skin lesions on the face or neck or
         arms [syn: {systemic lupus erythematosus}, {disseminated
         lupus erythematosus}]