The Collaborative International Dictionary of English v.0.48:

Sidewalk \Side"walk`\, n.
   A walk for foot passengers at the side of a street or road; a
   foot pavement. [U.S.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

sidewalk
    n 1: walk consisting of a paved area for pedestrians; usually
         beside a street or roadway [syn: sidewalk, pavement]

Moby Thesaurus II by Grady Ward, 1.0:

34 Moby Thesaurus words for "sidewalk":
   alameda, beaten path, beaten track, berm, bicycle path, boardwalk,
   bridle path, catwalk, esplanade, fastwalk, foot pavement, footpath,
   footway, garden path, groove, hiking trail, mall, parade, path,
   pathway, pavement, prado, promenade, public walk, run, runway, rut,
   towing path, towpath, track, trail, trottoir, walk, walkway