«لَا سدِّتْ كَر وَلَا طَاقِيَّهْ»

The image is a piece of fabric, the unnamed subject implied by the feminine verb, that someone hoped to turn into headwear. It is too short to serve as the length of cloth wound into a turban and too poor to sew into a light cap, so it ends up serving no purpose at all.

Applied more broadly, the saying describes anything caught between two possible uses and failing at both. It points to a thing whose inadequacy leaves it without value, falling short of the larger aim and the smaller one alike.

Use it when something, whether an object, a plan, or a compromise, proves too limited to serve either of the purposes it was meant for. It suits wry or mildly exasperated remarks about wasted materials or half-measures.