a very small twist of flax, wool, cotton, silk, or other fibrous substance, drawn out to considerable length; a compound cord consisting of two or more single yarns doubled, or joined together, and twisted.-a filament, as of a flower, or of any fibrous substance, as of bark; also, a line of gold or silver.-the prominent part of the spiral of a screw or nut; the rib. see screw, n., 1.-fig.: something continued in a long course or tenor; a,s the thread of life, or of a discourse.-fig.: composition; quality; fineness.-to pass a thread through the eye of; as, to thread a needle.-to pass or pierce through as a narrow way; also, to effect or make, as one's way, through or between obstacles; to thrid.-to form a thread, or spiral rib, on or in; as, to thread a screw or nut.