The Collaborative International Dictionary of English v.0.48:

Noose \Noose\, n. [Prob. fr. OF. nous, nom. sing. or acc. pl. of
   nou knot, F. n[oe]ud, L. nodus. Cf. Node.]
   A running knot, or loop, which binds the closer the more it
   is drawn.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Noose \Noose\ (n[=oo]z), v. t. [imp. & p. p. Noosed
   (n[=oo]zd); p. pr. & vb. n. Noosing.]
   To tie in a noose; to catch in a noose; to entrap; to
   insnare.
   [1913 Webster]

WordNet (r) 3.0 (2006):

noose
    n 1: a trap for birds or small mammals; often has a slip noose
         [syn: snare, gin, noose]
    2: a loop formed in a cord or rope by means of a slipknot; it
       binds tighter as the cord or rope is pulled [syn: noose,
       running noose, slip noose]
    v 1: make a noose in or of
    2: secure with a noose

Moby Thesaurus II by Grady Ward, 1.0:

158 Moby Thesaurus words for "noose":
   O, allure, and quarter, annular muscle, annulus, areola, aureole,
   ax, bag, bait, bait the hook, birdlime, block, bola, braid, catch,
   catch out, chaplet, circle, circuit, circumference, circus,
   closed circle, cobweb, corona, coronet, cross, crown, cycle,
   death chair, death chamber, decoy, diadem, discus, disk, dragnet,
   draw, drop, electric chair, enlace, enmesh, ensnare, ensnarl,
   entangle, entoil, entrap, entwine, enweb, eternal return,
   fairy ring, fishhook, fly, foul, gallows, gallows-tree, garland,
   gas chamber, gibbet, gill net, gin, glory, ground bait, guillotine,
   halo, halter, hang, harpoon, hemp, hempen collar, hook, hook in,
   hot seat, interknit, interlace, intertie, intertissue, intertwine,
   intertwist, interweave, intort, inveigle, jig, knit, lace, land,
   lariat, lasso, lethal chamber, lime, logical circle, loom, loop,
   looplet, lure, lynch, magic circle, maiden, mat, mesh, meshes,
   nail, neck, net, orbit, plait, pleach, plug, pound net,
   purse seine, raddle, radius, ring, rondelle, rope, round, roundel,
   sack, saucer, scaffold, scrag, seine, snag, snare, snarl, sniggle,
   spear, sphincter, spinner, splice, spread the toils, springe,
   squid, stake, stretch, string up, take, tangle, tangle up with,
   the chair, tissue, toils, trap, trawl, tree, trip, turn off, twill,
   twine, twist, vicious circle, wattle, weave, web, wheel, wind,
   wobbler, wreath, wreathe