thread, tightly twisted ply yarn having a circular cross section and used in commercial and home sewing machines and for hand sewing. Thread is usually wound on spools, with thread size, or degree of fineness, indicated on the spool end.
Cotton thread is compatible with fabrics made from yarn of plant origin, such as cotton and linen, and for rayon, made from cellulose, a plant substance. Silk is suitable for silks and wools, both of animal origin; and nylon and polyester are appropriate for synthetics and for knits having a high degree of stretch.