Soft fibres are materials that are made up of very small, thin strands. They are often used in clothing and other textiles, as well as for insulation and padding. The term 'soft fibres' can refer to a variety of materials, including cotton, wool, silk, and synthetic fibres such as polyester. The crossword solution for the term 'soft fibres' is 'FLUFF', which refers to the light, airy texture of these materials. FLUFF is often used to describe the softness of fabrics, as well as the lightness of insulation and padding.