What does "thread" mean?

Additional senses

1. 2.The prominent part of the spiral of a screw or nut; the rib. See Screw, n., 1.
2. 3.Fig.: Something continued in a long course or tenor; a,s the thread of life, or of a discourse. Bp. Burnet.
3. 4.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 (Zoöl.), a lasso cell. See under Lasso. -- Thread herring (Zoöl.), 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.
4. 5.To pass a thread through the eye of; as, to thread a needle.
5. 6.To pass or pierce through as a narrow way; also, to effect or make, as one's way, through or between obstacles; to thrid. Heavy trading ships . . . threading the Bosphorus. Mitford. They would not thread the gates. Shak.
6. 7.To form a thread, or spiral rib, on or in; as, to thread a screw or nut.