bolus hook

an instrument in a Jacquard loom that raises or lowers the harness, which carries and guides the warp thread so that the weft will either lie above or below it, which in turn creates the pattern.

ジャカード織機において綜絖を上下させる器具；模様を作り出すために緯糸が経糸の上または下を通るよう、経糸を保持して導く