Heddle
A cord or wire with a small eye that holds one warp thread, so that groups of threads can be raised or lowered together.
Also: heald, harness
Every warp thread on a loom passes through the eye of a heddle. The heddles are fixed in rows on frames called shafts. When the weaver presses a treadle, one shaft lifts and its warp threads rise while the others stay down. This opens a gap called the shed, and the shuttle crosses through it. The next treadle opens a different shed. Two shafts give plain weave. More shafts give twill, satin and many patterns. On a jacquard loom each warp thread, or each small group of threads, has its own heddle and can be lifted separately.