What is "thread herring"

Thread \Thread\ (thr[e^]d), n. [OE. threed, [thorn]red, AS. [thorn]r[=ae]d; akin to D. draad, G. draht wire, thread, OHG. dr[=a]t, Icel. [thorn]r[=a][eth]r a thread, Sw. tr[*a]d, Dan. traad, and AS. [thorn]r[=a]wan to twist. See Throw, and cf. Third.]

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.
   --Bp. Burnet.

5. Fig.: Composition; quality; fineness. [Obs.]

   A neat courtier, Of a most elegant thread.
   --B. Jonson.

6. (Computers) A related sequence of instructions or actions within a program that runs at least in part independent of other actions within the program; -- such threads are capable of being executed only in oprating systems permittnig multitasking.

7. (Computers) A sequence of messages posted to an on-line newsgroup or discussion group, dealing with the same topic; -- messages in such a thread typically refer to a previous posting, thus allowing their identification as part of the thread. Some news-reading programs allow a user to follow a single such thread independent of the other postings to that newsgroup.

   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 (Zo["o]l.), a lasso cell. See under Lasso.

   Thread herring (Zo["o]l.), 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.