Weaver's Reed is a term used to describe a tool used in weaving. It is also known as a sley, which is a four-letter word that is often used in crossword puzzles. The weaver's reed is a comb-like tool with metal teeth that is used to separate the warp threads of a loom and to push the weft thread into place. It is an essential tool for weaving and is used to create even and consistent fabric.