An authentic signature; (especially), the signature of a sovereign, used to validate a formal document.

(medicine) The presence of Koplik's spots.

An indication that someone is alive; vital sign. / (figuratively) An indication that someone is present.

(US) a road sign which instructs road users to give right of way to other traffic

The presence of calluses on the knuckles or back of the hand, caused by contact with the incisors during self-induced vomiting, generally a sign of an eating disorder.

(medicine) The unusual pairing of fever with bradycardia, seen in certain conditions such as yellow fever and typhoid fever.

(pathology) An indication of femoral deep vein thrombosis: it is the presence of dilated pretibial veins in the affected leg, which remain dilated on raising the leg.

An indirect measure of skeletal maturity, whereby the ossification stage of the iliac apophysis is used to judge the ossification of the spinal vertebrae.

(radiology) The finding of a dark halo around the arterial lumen on ultrasound, suggesting a diagnosis of temporal arteritis.

A handpainted advertising sign that has been preserved on a building for an extended period of time and has thus begun to fade.