an object, quality, or event whose presence or occurrence indicates the probable presence or occurrence of something else: flowers are often given as a sign of affection[with clause]:the shops are full, which is a sign that the recession is past its worst
- something regarded as an indication of what is happening or going to happen:the signs are that counterfeiting is growing at an alarming rate
- [with negative] used to indicate that someone or something is not where they should be or are expected to be:there was still no sign of her
- Medicine an indication of a disease detectable by a medical practitioner even if not apparent to the patient:clinical signs of liver disease Compare with symptom.
- a miracle regarded as evidence of supernatural power (chiefly in biblical and literary use):he observed signs and miracles taking place [mass noun] North American the trail of a wild animal: wolverine sign
(source: Oxford Dictionaries)