sure sign

47 Moby Thesaurus words for "sure sign":
      absolute indication, badge, banner, burden of proof, character,
      characteristic, conclusive evidence, damning evidence,
      demonstration, determination, device, differentia, earmark,
      establishment, hallmark, idiosyncrasy, image,
      incontrovertible evidence, index, indicant, indicator,
      indisputable evidence, insignia, ironclad proof, keynote, mark,
      measure, note, onus, onus probandi, peculiarity, picture, proof,
      property, representation, representative, seal, settlement, sigil,
      sign, signal, signature, stamp, symptom, telltale sign, trait,
      unmistakable sign