WordNet (r) 3.0 (2006):

public opinion
    n 1: a belief or sentiment shared by most people; the voice of
         the people; "he asked for a poll of public opinion" [syn:
         public opinion, popular opinion, opinion, vox
         populi]

Moby Thesaurus II by Grady Ward, 1.0:

52 Moby Thesaurus words for "public opinion":
   assumption, attitude, backscratching, climate of opinion,
   common belief, community sentiment, conceit, concept, conception,
   conclusion, consensus gentium, consideration, estimate, estimation,
   ethos, eye, feeling, general belief, idea, impression,
   influence peddling, judgment, lights, lobbying, lobbyism,
   logrolling, mind, mystique, notion, observation, opinion,
   personal judgment, point of view, political influence,
   popular belief, position, posture, presumption, prevailing belief,
   public belief, reaction, sentiment, sight, social pressure,
   special-interest pressure, stance, theory, thinking, thought, view,
   way of thinking, wire-pulling