The Collaborative International Dictionary of English v.0.48:

Frazzle \Fraz"zle\, v. t. [imp. & p. p. Frazzled; p. pr. & vb.
   n. Frazzling.] [Cf. G. faseln, and E. fray.]
   To fray; to wear or pull into tatters or tag ends; to tatter;
   -- used literally and figuratively. [Prov. Eng. & U. S.]
   [Webster 1913 Suppl.]

         Her hair was of a reddish gray color, and its frazzled
         and tangled condition suggested that the woman had
         recently passed through a period of extreme excitement.
                                                  --J. C.
                                                  Harris.
   [Webster 1913 Suppl.]

The Collaborative International Dictionary of English v.0.48:

Frazzle \Fraz"zle\, n.
   1. The act or result of frazzling; the condition or quality
      of being frazzled; the tag end; a frayed-out end. [Prov.
      Eng. & U. S.]
      [Webster 1913 Suppl. +PJC]

            My fingers are all scratched to frazzles. --Kipling.
      [Webster 1913 Suppl.]

   2. a state of extreme exhaustion; -- often used in the phrase

   worn to a frazzle. [WordNet sense 1]
      [WordNet 1.5]

            Gordon had sent word to Lee that he "had fought his
            corps to a frazzle."                  --Nicolay &
                                                  Hay (Life of
                                                  Lincoln).
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

frazzle
    n 1: a state of extreme exhaustion; "he was worn to a frazzle"
    v 1: wear away by rubbing; "The friction frayed the sleeve"
         [syn: fray, frazzle]
    2: exhaust physically or emotionally; "She was frazzled after
       the visit of her in-laws"

Moby Thesaurus II by Grady Ward, 1.0:

135 Moby Thesaurus words for "frazzle":
   ablate, abrade, abrase, abrasion, agitate, bark, beat, blemish,
   bloody, bother, break, bugger, burn, burn out, chafe, check, chip,
   claw, concern, concussion, crack, crackle, craze, cut, debilitate,
   disquiet, distress, disturb, do in, do up, enervate, erase, erode,
   exhaust, fag, fag out, fatigue, file, flag, flash burn, fracture,
   fray, fret, gall, gash, give concern, gnaw, gnaw away, grate,
   graze, grind, harass, hurt, incise, incision, injure, injury, jade,
   knock out, knock up, lacerate, laceration, lesion, maim,
   make mincemeat of, maul, mortal wound, mutilate, mutilation,
   outwear, overfatigue, overstrain, overtire, overweary, pierce,
   poop, poop out, prostrate, puncture, rasp, raze, rend, rent, rip,
   rub away, rub off, rub out, run, rupture, savage, scald, scorch,
   scotch, scour, scrape, scratch, scrub, scuff, second-degree burn,
   skin, slash, slit, sore, sprain, stab, stab wound, stick, strain,
   tatter, tear, third-degree burn, tire, tire out, tire to death,
   trauma, traumatize, trouble, tucker, upset, use up, weaken, wear,
   wear away, wear down, wear off, wear on, wear out, wear ragged,
   weary, weather, wilt, wind, wound, wounds immedicable, wrench