Wordnet 3.0
NOUN (1)
1. 
 a very steep cliff; 
The Collaborative International Dictionary of English v.0.48:
Precipice \Prec"i*pice\, n. [F. pr['e]cipice, L. praecipitium,
   fr. praeceps, -cipitis, headlong; prae before + caput,
   capitis, the head. See Pre-, and Chief.]
   1. A sudden or headlong fall. [Obs.] --Fuller.
      [1913 Webster]
   2. A headlong steep; a very steep, perpendicular, or
      overhanging place; an abrupt declivity; a cliff.
      [1913 Webster]
            Where wealth like fruit on precipices grew.
                                                  --Dryden.
      [1913 Webster]
WordNet (r) 3.0 (2006):
precipice
    n 1: a very steep cliff
Moby Thesaurus II by Grady Ward, 1.0:
25 Moby Thesaurus words for "precipice":
   bluff, cliff, crag, crest, escarpment, face, hilltop, knoll,
   lofty peak, mountaintop, palisade, palisades, peak, pic, pico,
   pike, pinnacle, point, scar, scarp, spur, steep, summit, tor,
   wall