Sign meaning : (sometimes also used uncountably) A visible indication. Physical evidence left by an animal. A clearly visible object, generally flat, bearing a short message in words or pictures. A wonder; miracle; prodigy. An astrological sign. Positive or negative polarity, as denoted by the + or - sign. A specific gesture or motion used to communicate by those with speaking or hearing difficulties; now specifically, a linguistic unit in sign language equivalent to word in spoken languages. Sign language in general. An omen. A property of the body that indicates a disease and, unlike a symptom, is unlikely to be noticed by the patient. A military emblem carried on a banner or standard.