Well, here's what I got from dictionary.com (and surprisingly, NOT from merriam-webster, didn't find anything for that)

-----------------------------------------------------------

sleaving

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


Source: Webster's Revised Unabridged Dictionary, © 1996, 1998 MICRA, Inc.

-----------------------------------------------------------

and as for sheaving :


sheave1
tr.v. sheaved, sheav·ing, sheaves
To collect and bind into a sheaf.

[From sheaf.]

Source: The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2000 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.

-----------------------------------------------------------

Still, how can I verify it in British English? Hmm.....