n.
     - a person's name written in a distinctive way as a form of identification or authorization. ▸the action of signing a document. 
- a distinctive product, feature, etc. by which someone or something can be identified: 
[as modifier]
 the chef's signature dish. 
- Music  short for key signature or time signature.
- Printing  a letter or figure printed at the foot of one or more pages of each sheet of a book as a guide in binding. ▸a printed sheet after being folded to form a group of pages. 
- N. Amer. the part of a medical prescription that gives instructions about the use of the medicine or drug prescribed.
Etymology
  C16: from med. L. signatura ‘sign manual’, from L. signare ‘to sign, mark’.