protocol

noun

pro·​to·​col ˈprō-tə-ˌkȯl 

-ˌkōl,

-ˌkäl,

-kəl

1

: an original draft, minute, or record of a document or transaction

2

a

: a preliminary memorandum often formulated and signed by diplomatic negotiators as a basis for a final convention or treaty

b

: the records or minutes of a diplomatic conference or congress that show officially the agreements arrived at by the negotiators

3

a

: a code prescribing strict adherence to correct etiquette and precedence (as in diplomatic exchange and in the military services)

a breach of protocol

b

: a set of conventions governing the treatment and especially the formatting of data in an electronic communications system

network protocols

c

: convention sense 3a,b

4

: a detailed plan of a scientific or medical experiment, treatment, or procedure

Did you know?

Protocol and Politics

In Late Greek, the word prōtokollon referred to the first sheet of a papyrus roll bearing the date of its manufacture. In some instances, it consisted of a flyleaf that was glued to the outside of a manuscript's case and provided a description of its contents. Coming from the Greek prefix prōt- ("first") and the verb kollan ("to glue together"), prōtokollon gave us our word protocol. In its earliest uses in the 15th century, the word referred to a record of a document or transaction. By the turn of the 18th century it was being used for the original record or minutes of a diplomatic negotiation, and still later for the etiquette observed by heads of state in ceremonies and relations with other dignitaries. This sense has since extended in meaning to cover any code of proper conduct.

Examples of protocol in a Sentence

Typically, those who make pronouncements like this assume (without saying so) that the tongues making up the multitude will belong to persons who are committed to the protocols of rational inquiry; frivolous persons, persons who exploit those protocols or play with them to gain political ends, are not imagined. —Stanley Fish, Harper's, December 2005

Purcell even flouted the timeless protocol of pretending to admire the work of his fellow editors. —Tobias Wolff, Old School, 2003

Today, thanks to the civil-rights movement, white guilt is propriety—an utterly invisible code that defines decency in our culture with thousands of little protocols we no longer even think about. —Shelby Steele, Harper's, November 2002

The soldier's actions constitute a breach of military protocol.

They did not follow the proper diplomatic protocols.

What is the proper protocol for declining a job offer?

the Geneva Protocol of 1925

Recent Examples on the Web

The patent for this low-latency wireless communication protocol, spearheaded by NREL power electronics Sarwar Islam, is pending. —Prabhat Ranjan Mishra, Interesting Engineering, 13 Sep. 2025

These deposits, placed and managed in a blockchain or DeFi protocol have more than doubled since April, and reflect the overall shift in both policy directives and investor sentiment. —Sean Stein Smith, Forbes.com, 13 Sep. 2025

The fatal attack has raised concerns about campus public-safety protocols, political violence, gun control and free speech. —Mandy Taheri joshua Rhett Miller, MSNBC Newsweek, 12 Sep. 2025

School board members applauded the staff’s quick reaction and that the safety protocols seemed to work. —Karen Billing, San Diego Union-Tribune, 12 Sep. 2025

Word History

Etymology

Middle French prothocole, from Medieval Latin protocollum, from Late Greek prōtokollon first sheet of a papyrus roll bearing date of manufacture, from Greek prōt- prot- + kollan to glue together, from kolla glue; perhaps akin to Middle Dutch helen to glue

First Known Use

1541, in the meaning defined at sense 1

Phrases Containing protocol

• hypertext transfer protocol

Rhymes for protocol

• aerosol
• alcohol
• arbitral
• basketball
• butanol
• cannonball
• carbinol
• catarrhal
• cortisol
• ethanol
• fireball
• gasohol

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Kids Definition

protocol

noun

pro·​to·​col ˈprōt-ə-ˌkȯl 

1

: an original copy or record of a document

2

: a code of diplomatic or military rules of behavior

3

: a set of rules for the formatting of data in an electronic communications system

network protocols

Medical Definition

protocol

noun

pro·​to·​col ˈprōt-ə-ˌkȯl, -ˌkōl, -ˌkäl 

1

: an official account of a proceeding

especially : the notes or records relating to a case, an experiment, or an autopsy

2

: a detailed plan of a scientific or medical experiment, treatment, or procedure

cryotherapy was performed in approximately half of the eyes through a randomization protocol

—The Journal of the American Medical Association

Legal Definition

protocol

noun

pro·​to·​col ˈprō-tə-ˌkȯl 

1

: an original draft, minute, or record of a document or transaction

2

a

: a preliminary memorandum often formulated and signed by diplomatic negotiators as a basis for a final convention or treaty

b

: the records or minutes of a diplomatic conference or congress that show officially the agreements arrived at by the negotiators