[1] : The Collaborative International Dictionary of English v.0.48

hummock \hum"mock\, n. prob. a dim. of hump. see hump.
   1. a rounded knoll or hillock; a rise of ground of no great
      extent, above a level surface.
      1913 webster

   2. a ridge or pile of ice on an ice field.
      1913 webster

   3. timbered land. see hammock. southern u.s.
      1913 webster
see also:
hump hammock 

[2] : WordNet (r) 2.0

hummock
     n : a small natural hill syn: knoll, mound, hillock, hammock
see also:
knoll mound hillock hammock 

[3] : Moby Thesaurus II by Grady Ward, 1.0

20 moby thesaurus words for "hummock":
   anthill, barrow, brae, butte, down, drumlin, dune, fell, foothills,
   hill, hillock, knob, knoll, molehill, monticle, monticule, moor,
   mound, sand dune, swell

Hummock >> H Words
Hummock, definition of term: Hummock
hummock_pag1.html