sheathe

from The American Heritage® Dictionary of the English Language, 5th Edition.

• transitive verb To insert into or provide with a sheath.
• transitive verb To retract (a claw) into a sheath.
• transitive verb To enclose with a protective covering; encase.

from The Century Dictionary.

• To put into a sheath or scabbard; inclose in or cover with or as with a sheath or case: as, to sheathe a sword or dagger.
• To protect by a casing or covering; cover over or incase, as with armor, boards, iron, sheets of copper, or the like.
• To cover up or hide.
• To render less sharp or keen; mask; dull.

from the GNU version of the Collaborative International Dictionary of English.

• transitive verb To put into a sheath, case, or scabbard; to inclose or cover with, or as with, a sheath or case.
• transitive verb To fit or furnish, as with a sheath.
• transitive verb To case or cover with something which protects, as thin boards, sheets of metal, and the like.
• transitive verb rare To obtund or blunt, as acrimonious substances, or sharp particles.
• transitive verb to make peace.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• verb To put something, such as a knife, into a sheath
• verb To encase something with a protective covering

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb plunge or bury (a knife or sword) in flesh
• verb cover with a protective sheathing
• verb enclose with a sheath