bed screw

from The Century Dictionary.

• noun A bed-key or bedwrench.
• noun Same as barrel-screw.

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

• (Naut.) A form of jack screw for lifting large bodies, and assisting in launching.
• A long screw formerly used to fasten a bedpost to one of the adjacent side pieces.

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

• noun nautical A form of jack screw for lifting large bodies and assisting in launching.
• noun A long screw formerly used to fasten a bedpost to one of the adjacent side pieces.