# signature

Pronunciation: US say "SIG-nuh-chur" /ˈsɪɡnət͡ʃɚ/; UK say "SIG-nuh-chuh" /ˈsɪɡnət͡ʃə(ɹ)/; AUS say "SIG-ni-chuh" /ˈsɪɡnɪt͡ʃə(ɹ)/

## Noun

1. A person's name written in their own hand, used to identify them or to show approval of an accompanying document such as a contract.
   - Simple: Your name written in your own hand, used to show you agree or to prove who you are.
   - _The contract required a signature from both parties before it became valid._
   - _Forgers spend years learning to copy famous signatures._
3. A distinguishing feature or product that marks out a particular person, brand, or place.
   - Simple: A special feature or product that one person, place, or business is known for.
   - _The hotel's rooftop garden has become its signature._
   - _Bold brass sections are a signature of the composer's later works._
4. Text or images appended to the end of a user's emails, forum posts, and similar messages, adding a personal touch or contact information.
   - Simple: Lines added to the end of your emails or posts, often with your name and contact details.
   - _Add a link to your portfolio in your email signature._
   - _His forum signature featured a quote from his favorite poet._
5. The act of signing one's name, or of producing one's written name.
   - Simple: The act of writing your name to sign something.
   - _The ceremony concluded with the signature of the peace accord._
   - _A single signature sealed the merger after weeks of talks._
6. Data appended to a message that serves to verify it was sent by the source it claims to be from.
   - Simple: Special data added to a message that proves it really came from who it says.
   - _The software rejected the download because its signature did not match._
   - _Email servers use digital signatures to confirm that a message has not been altered._
7. Signs at the beginning of the staff indicating the key and tempo, made up of the key signature and the time signature.
   - Simple: Marks at the start of written music that show the key and the beat.
   - _The conductor reminded the players to check the signature before starting._
   - _A change in the signature midway through the piece surprised the audience._
8. A pattern used to match the identity of a virus, the parameter types of a method, or similar code features.
   - Simple: A pattern used to spot a known computer virus or recognize a piece of code.
   - _The scanner flagged the file because it matched a known malware signature._
   - _Two methods can share a name as long as their signatures differ._
9. A group of four sheets, or a multiple of four, printed so that when folded they form one section of a book.
   - Simple: A group of printed sheets folded together to make one section of a book.
   - _The binder stacked each signature in order before stitching the spine._
   - _A damaged signature meant several pages had to be reprinted._
10. A mark or sign that points to or implies something else.
   - Simple: A clear sign that shows or hints at something.
   - _Rising sea levels are a signature of a warming planet._
   - _The blast left a signature in the rock that geologists could later read._
11. The part of a doctor's prescription that gives the patient directions for taking the medicine.
   - Simple: The part of a prescription that tells the patient how to take the medicine.
   - _The signature on the prescription read 'one tablet twice daily with food.'_
   - _A vague signature can leave a patient unsure how often to take a drug._
12. A tuple that records the signs of the coefficients when a quadratic form is written in any of its diagonal forms.
   - Simple: In math, a list showing the plus and minus signs of a quadratic form written using only squared terms.
   - _She computed the signature of the quadratic form to classify the surface._
   - _Two forms with the same signature are equivalent over the real numbers._

## Adjective

2. Distinctive and characteristic, marking something as clearly belonging to a particular person, group, or thing.
   - Simple: Special and easy to recognize as belonging to one person or thing.
   - _The band opened with their signature song._
   - _His signature move on the court is a quick spin to the left._

## Noun

13. A supposed resemblance between a disease's outward signs and some physical thing, taken to point to that thing as a remedy: as the red skin of scarlet fever was matched to red cloth. *(obsolete)*
   - Simple: An old belief that a disease and its cure look alike, such as a red cloth matching a fever's red skin.
   - _Following the doctrine, the apothecary saw a signature between the lungwort's spotted leaves and diseased lungs._
   - _Each plant's signature, physicians once believed, revealed the malady it was meant to cure._

## Origin

This word was borrowed from Middle French signature, or from Medieval Latin signatura, formed from the verb signare (from signum, 'sign') plus a suffix. It replaced the native Old English handseten, literally 'hand setting'.

Source: DictionaryAI, https://dictionaryai.com/define/signature (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).