The Collaborative International Dictionary of English v.0.48:

Sleave \Sleave\ (sl[=e]v), n. [Cf. Dan. sl["o]if, a knot loop,
   Sw. slejf, G. schleife a knot, sliding knot, and E. slip,
   v.i.]
   (a) The knotted or entangled part of silk or thread.
   (b) Silk not yet twisted; floss; -- called also sleave
       silk.
       [1913 Webster]

             Sleep that knits up the ravell'd sleave of care.
                                                  --Shak.
       [1913 Webster]