The DICT Development Group

  89 Moby Thesaurus words for "tighten":
     affix, anchor, annex, attach, back, belay, box, box in, box up,
     brace, cement, cinch, circumscribe, clamp, clinch, close, compress,
     confine, continue, cramp, crank, crank in, crush, drag out, draw,
     draw in, draw out, draw taut, elongate, engraft, ensphere, extend,
     fasten, fix, graft, grapple, hem, hem in, keep from spreading,
     keep within bounds, knit, lengthen, lengthen out, let out, limit,
     localize, make fast, moor, narrow, nip, pinch, press, produce,
     prolong, prolongate, protract, pull, pull in, put to, qualify,
     reel, reel in, reinforce, restrict, rigidify, screw up, secure,
     set, set to, shore up, spin out, squeeze, stiffen, stint, strain,
     strengthen, stretch, stretch out, string out, tackle, tauten,
     tense, trice up, trim, tweak, wad up, winch, wind in, windlass