The Collaborative International Dictionary of English v.0.48:

Sleave \Sleave\, v. t. [imp. & p. p. Sleaved (sl[=e]vd); p.
   pr. & vb. n. Sleaving.]
   To separate, as threads; to divide, as a collection of
   threads; to sley; -- a weaver's term.
   [1913 Webster]