The Collaborative International Dictionary of English v.0.48:

Sle \Sle\ (sl[=e]), v. t.
   To slay. [Obs.] --Chaucer.
   [1913 Webster]

WordNet (r) 3.0 (2006):

SLE
    n 1: 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, SLE, disseminated
         lupus erythematosus]

V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

SLE
       Screen List Editing