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. [1913 Webster]

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. [1913 Webster]

3.  The prominent part of the spiral of a screw or nut; the rib. See Screw, n., 1. [1913 Webster]

4.  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. [1913 Webster]

5.  Fig.: Composition; quality; fineness. [1913 Webster]
"A neat courtier,
Of a most elegant thread." [1913 Webster]

6.  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. [PJC]

7.  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. [PJC]

1.  To pass a thread through the eye of; as, to thread a needle. [1913 Webster]

2.  To pass or pierce through as a narrow way; also, to effect or make, as one's way, through or between obstacles; to thrid. [1913 Webster]
"Heavy trading ships . . . threading the Bosphorus." [1913 Webster]
"They would not thread the gates." [1913 Webster]

3.  To form a thread, or spiral rib, on or in; as, to thread a screw or nut. [1913 Webster]

thread, n. & v.
--n.
1 a a spun-out filament of cotton, silk, or glass etc.; yarn. b a length of this.
2 a thin cord of twisted yarns used esp. in sewing and weaving.
3 anything regarded as threadlike with reference to its continuity or connectedness (the thread of life; lost the thread of his argument).
4 the spiral ridge of a screw.
5 (in pl.) sl. clothes.
6 a thin seam or vein of ore.
--v.tr.
1 pass a thread through the eye of (a needle).
2 put (beads) on a thread.
3 arrange (material in a strip form, e.g. film or magnetic tape) in the proper position on equipment.
4 make (one's way) carefully through a crowded place, over a difficult route, etc.
5 streak (hair etc.) as with threads.
6 form a screw-thread on.

Idiom:
hang by a thread be in a precarious state, position, etc. thread mark a mark in the form of a thin line made in banknote paper with highly coloured silk fibres to prevent photographic counterfeiting.

Derivative:
threader n. threadlike adj.

Etymology:
OE thr{aelig}d f. Gmc

VB  reduce to order, bring into order, introduce order into, rally, arrange, dispose, place, form, put in order, set in order, place in order, set out, collocate, pack, marshal, range, size, rank, group, parcel out, allot, distribute, deal, cast the parts, assign the parts, dispose of, assign places to, assort, sort, sift, riddle, put to rights, set to rights, put into shape, put in trim, put in array, apportion, class, classify, divide, file, string together, thread, register, catalogue, tabulate, index, graduate, digest, grade, methodize, regulate, systematize, coordinate, organize, settle, fix, unravel, disentangle, ravel, card, disembroil, feaze.

N  continuity, consecution, consecutiveness, succession, round, suite, progression, series, train chain, catenation, concatenation, scale, gradation, course, ceaselessness, constant flow, unbroken extent, procession, column, retinue, cortege, cavalcade, rank and file, line of battle, array, pedigree, genealogy, lineage, race, ancestry, descent, family, house, line, line of ancestors, strain, rank, file, line, row, range, tier, string, thread, team, suit, colonnade, continuous, continued, consecutive, progressive, gradual, serial, successive, immediate, unbroken, entire, linear, in a line, in a row, uninterrupted, unintermitting, unremitting, unrelenting (perseverence), perennial, evergreen, constant, continuously, seriatim, in a line, in succession, in turn, running, gradually, step by step, gradatim, at a stretch, in file, in column, in single file, in Indian file.

VB  follow in a series, form a series, fall in, arrange in a series, collate, string together, file, thread, graduate, organize, sort, tabulate.

N  weakness, debility, atony, relaxation, languor, enervation, impotence, infirmity, effeminacy, feminality, fragility, flaccidity, inactivity, anaemia, bloodlessness, deficiency of blood, poverty of blood, declension of strength, loss of strength, failure of strength, delicacy, invalidation, decrepitude, asthenia, adynamy, cachexy, cachexia, sprain, strain, reed, thread, rope of sand, house of cards, softling, weakling, infant, youth, weak, feeble, debile, impotent, relaxed, unnerved sapless, strengthless, powerless, weakly, unstrung, flaccid, adynamic, asthenic, nervous, soft, effeminate, feminate, womanly, frail, fragile, shattery, flimsy, unsubstantial, insubstantial, gimcrack, gingerbread, rickety, creaky, creaking, cranky, craichy, drooping, tottering, broken, lame, withered, shattered, shaken, crazy, shaky, palsied, decrepit, languid, poor, infirm, faint, faintish, sickly, dull, slack, evanid, spent, short-winded, effete, weather-beaten, decayed, rotten, worn, seedy, languishing, wasted, washy, laid low, pulled down, the worse for wear, unstrengthened, unsupported, unaided, unassisted, aidless, defenseless, cantilevered (support), on its last legs, weak as a child, weak as a baby, weak as a chicken, weak as a cat, weak as a rat, weak as water, weak as water gruel, weak as gingerbread, weak as milk and water, colorless, non sum qualis eram.

N  filament, line, fiber, fibril, funicle, vein, hair, capillament, cilium, cilia, pilus, pili, tendril, gossamer, hair stroke, veinlet, venula, venule, wire, string, thread, packthread, cotton, sewing silk, twine, twist, whipcord, tape, ribbon, cord, rope, yarn, hemp, oakum, jute, strip, shred, slip, spill, list, band, fillet, fascia, ribbon, riband, roll, lath, splinter, shiver, shaving, beard, ramification, strand, filamentous, filamentiferous, filaceous, filiform, fibrous, fibrillous, thread-like, wiry, stringy, ropy, capillary, capilliform, funicular, wire-drawn, anguilliform, flagelliform, hairy, taeniate, taeniform, taenioid, venose, venous.

VB  pass, pass through, perforate, penetrate, permeate, thread, thrid, enfilade, go through, go across, go over, pass over, cut across, ford, cross, pass and repass, work, make one's way, thread one's way, worm one's way, force one's way, make a passage form a passage, cut one's way through, find its way, find its vent, transmit, make way, clear the course, traverse, go over the ground.

golden thread, hang by a thread, lisle thread, pack thread, screw thread, thread blight, thread maker