The Collaborative International Dictionary of English v.0.48:

handful \hand"ful\ (h[a^]nd"f[.u]l), n.; pl. handfuls
   (h[a^]nd"f[.u]lz). [AS. handfull.]
   1. As much as the hand will grasp or contain. --Addison.
      [1913 Webster]

   2. A hand's breadth; four inches. [Obs.]
      [1913 Webster]

            Knap the tongs together about a handful from the
            bottom.                               --Bacon.
      [1913 Webster]

   3. A small quantity or number.
      [1913 Webster]

            This handful of men were tied to very hard duty.
                                                  --Fuller.
      [1913 Webster]

   4. A person, task, or situation, which is the most that one
      can manage; as, my two-year-old is a handful.
      [PJC]

   To have one's handful, to have one's hands full; to have
      all one can do. [Obs.]
      [1913 Webster]

            They had their handful to defend themselves from
            firing.                               --Sir. W.
                                                  Raleigh.
      [1913 Webster]

WordNet (r) 3.0 (2006):

handful
    n 1: a small number or amount; "only a handful of responses were
         received" [syn: handful, smattering]
    2: the quantity that can be held in the hand [syn: handful,
       fistful]

Moby Thesaurus II by Grady Ward, 1.0:

87 Moby Thesaurus words for "handful":
   Augean task, Herculean task, a few, ace, atom, backbreaker,
   ballbuster, bit, bitch, bother, chore, couple, dab, dead lift,
   dole, dot, dram, dribble, driblet, dwarf, farthing, few, fistful,
   fleck, flyspeck, fragment, gobbet, grain, granule, groat, hair,
   hard job, hard pull, heavy sledding, iota, jot, large order,
   limited number, little, little bit, man-sized job, minim, minimum,
   minutiae, mischief-maker, mite, modicum, molecule, mote, nuisance,
   nutshell, only a few, ounce, particle, pebble, piddling few,
   piddling number, pinch, pittance, point, rough go, scattering,
   scruple, small number, smatter, smattering, smidgen, smitch,
   spatter, spattering, speck, spoonful, spot, sprinkling, tall order,
   thimbleful, tiny bit, tittle, too few, tough job,
   tough proposition, trickle, trifling amount, trivia, troublemaker,
   uphill work, whit