molehill

molehill
    n 1: a mound of earth made by moles while burrowing
    

Molehill \Mole"hill`\, n.
   A little hillock of earth thrown up by moles working under
   ground; hence, a very small hill, or an insignificant
   obstacle or difficulty; as, to make a mountain out of a
   molehill.
   [1913 Webster]

         Having leapt over such mountains, lie down before a
         molehill.                                --South.
   [1913 Webster] mMolendinaceous
    

92 Moby Thesaurus words for "molehill":
      a continental, a curse, a damn, a darn, a hoot, anthill, bagatelle,
      bank, barrow, bauble, bean, bibelot, bit, brae, brass farthing,
      butte, button, cent, cock, curio, down, drift, drumlin, dune,
      embankment, farce, farthing, feather, fell, fig, fleabite,
      folderol, foothills, fribble, frippery, gaud, gewgaw, gimcrack,
      hair, halfpenny, haycock, haymow, hayrick, haystack, heap, hill,
      hill of beans, hillock, hummock, jest, joke, kickshaw, knickknack,
      knickknackery, knob, knoll, minikin, mockery, monticle, monticule,
      moor, mound, mow, peppercorn, picayune, pile, pin, pinch of snuff,
      pinprick, pyramid, rap, red cent, rick, row of pins, rush,
      sand dune, shit, snap, sneeshing, snowdrift, sou, stack, straw,
      swell, toy, trifle, trinket, triviality, tuppence, two cents,
      twopence, whim-wham