1. the soft, fine wool fibers that grow close to a sheep’s skin beneath the outer coat
Usage: textile industry; plural form

Examples

• The mill specialized in processing underwools for luxury garments.
• Underwools provide excellent insulation due to their fine texture.
• The shepherd carefully separated the underwools from the coarser outer fibers.
• Premium sweaters are often made from the softest underwools.
• The quality of underwools varies significantly between different sheep breeds.