Thread n.
 1. 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; also, one fiber of a cord composed of multiple fibers.
 2. A filament of any substance, as of glass, gold or silver; a filamentous part of an object, such as a flower; a component fiber of any or of any fibrous substance, as of bark.
 3. The prominent part of the spiral of a screw or nut; the rib. See Screw, n., 1.
 4. (Fig.) Something continued in a long course or tenor; a recurrent theme or related sequence of events in a larger story; as the thread of a story, or of life, or of a discourse.
 5. Fig.: Composition; quality; fineness. [Obs.]
 A neat courtier,
 Of a most elegant thread.   --B. Jonson.
 Air thread, the fine white filaments which are seen floating in the air in summer, the production of spiders; gossamer.
 Thread and thrum, the good and bad together. [Obs.] --Shak.
 Thread cell Zool., a lasso cell. See under Lasso.
 Thread herring Zool., the gizzard shad. See under Gizzard.
 Thread lace, lace made of linen thread.
 Thread needle, a game in which children stand in a row, joining hands, and in which the outer one, still holding his neighbor, runs between the others; -- called also thread the needle.