1. An opinion that looks like a fact to you
  2. Opinion given to you, instead of developed in-house
  3. An opinion without an editable rationale structure
  4. An opinion that was on your neural net before you've internalized critical thinking
  5. value-neutral term for prejudice
  6. doublespeak, since opinions are supposed to be formed by the owner

    artfuldodger has a nice tongue-in-cheek variant on this under decompiling memes