- 1) That part of the prescription that contains the doctor's directions to the patient. For example, the signature might say “take twice daily with food”. Also known as the sig.. 2) The outward appearance of a natural object, which was once taken as a token of its special properties. This ancient doctrine of signatures led some to conclude that the walnut, which looks something like a tiny brain, could be used to heal brain problems; the liverwort plant, which has a three-lobed liver-like leaf, was useful in treating liver disease; and so on. Not too many physicians accept such fanciful ideas today. The word "signature" comes from the Latin "signare" meaning "to sign or mark."
* * *The part of a prescription containing the directions to the patient. [Mediev. L. signatura, fr. L. signum, a sign, mark]
* * *1) a feature in the appearance or qualities of a natural object formerly held to indicate its utility in medicine either because of a fancied resemblance to a body part (as a heart-shaped leaf indicating utility in heart disease) or because of a presumed relation to some phase of a disease (as the prickly nature of thistle indicating utility in case of a stitch in the side)2) the part of a medical prescription which contains the directions to the patient
* * *sig·na·ture (sigґnə-chər) [L. signatura] 1. the part of a prescription that gives directions to the patient for taking of medicine; abbreviated S. or sig. See prescription. 2. a characteristic feature of a substance that in folk medicine may be regarded as an indicator of its medicinal virtues: the eyelike mark on the flower of the euphrasia was considered to show its usefulness in eye diseases; the liverlike shape of the leaf of liverwort pointed to its use in hepatic diseases; and the yellow color of saffron indicated its use in jaundice.
Medical dictionary. 2011.