superincumbent

from WordNet (r) 3.0 (2006)

superincumbent
    adj 1: lying or resting on and exerting pressure on something
           else; "superincumbent layers of dead plants cut off the
           air and arrested decomposition"

from The Collaborative International Dictionary of English v.0.48

Superincumbent \Su`per*in*cum"bent\, a. [L. superincumbens, p.
   pr. of superincumbere. See {Super-}, and {Incumbent}.]
   Lying or resting on something else.
   [1913 Webster]

from Moby Thesaurus II by Grady Ward, 1.0

38 Moby Thesaurus words for "superincumbent":
      beetle, beetle-browed, beetling, bridging, burdensome, cumbersome,
      cumbrous, demanding, exacting, exigent, greater, grievous, higher,
      imbricate, impendent, impending, incumbent, jutting, lapping,
      lowering, lumpish, massive, onerous, oppressive, over, overarched,
      overhanging, overhung, overlapping, overlying, pending, projecting,
      shingled, spanning, taxing, tough, unwieldy, weighty

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