A case or covering for a sword.
Then Simon Peter having a sword drew it, and smote the high priest's servant, and cut off his right ear. The servant's name was Malchus. Then said Jesus unto Peter, Put up thy sword into the SHEATH: the cup which my Father hath given me, shall I not drink it? ( John 18:10-11 )
Bibliography Information"Entry for 'Sheath'". A King James Dictionary.