Borrowed from Middle French protocolle, protocole, from Late Latin protocollum, from gkm πρωτόκολλον, from πρῶτος ("first") + κόλλα ("glue").

• (RP) IPA: /ˈpɹəʊtəˌkɒl/
• (America) IPA: /ˈpɹoʊtəˌkɑl/, /ˈpɹoʊtəˌkɔl/, /ˈpɹoʊtəˌkoʊl/

protocol

1. (now chiefly historical) The minutes, or official record, of a negotiation or transaction; especially a document drawn up officially which forms the legal basis for subsequent agreements based on it. [from 15th c.]
   • 1842, Thomas Campbell, Frederick the Great and his Times, volume II, page 47:

     Another account says that, on the morning of the 31st of May, the king delivered to the prince-royal the crown, the sceptre, and the key of his treasure and gave him his blessing. The privy-counsillor Vockerodt drew up at his desire a protocol of the transaction.

2. (international law, now rare) An official record of a diplomatic meeting or negotiation; later specifically, a draft document setting out agreements to be signed into force by a subsequent formal treaty. [from 17th c.]
   • 1970, Matthew Smith Anderson, The Great Powers and the Near East, 1774-1923, page 32:

     The terms of this protocol formed the basis for the Treaty of London signed by the British, French and Russian governments on 6 July 1827.

3. (international law) An amendment to an official treaty. [from 19th c.]
   • 2002, Philippe Sands, Principles of International Environmental Law, p. 917 n. 253:

     The 1992 Protocol amended the definitions of other terms, including ‘ship’, ‘oil’ and ‘incident’: Art. 2.

4. The first leaf of a roll of papyrus, or the official mark typically found on such a page. [from 19th c.]
   • 1991, Leila Avrin, Scribes, Script, and Books, page 146:

     They marked the beginning of each scroll with their protocol, a practice that continued in the papyrus trade in the Byzantine Empire [...] into the Islamic period, when there were bilingual protocols in Greek and Arabic.

5. The official formulas which appeared at the beginning or end of certain official documents such as charters, papal bulls etc. [from 19th c.]
6. (sciences) The original notes of observations made during an experiment. [from 19th c.]
7. (sciences) The precise method for carrying out or reproducing a given experiment. [from 19th c.]
8. The official rules and guidelines for heads of state and other dignitaries, governing accepted behaviour in relations with other diplomatic representatives or over affairs of state. [from 19th c.]
9. (by extension) An accepted code of conduct; acceptable behaviour in a given situation or group. [from 20th c.]
10. (computing) A set of formal rules describing how to transmit or exchange data, especially across a network. [from 20th c.]
    • 2006, Zheng & Ni, Smart Phone and Next-Generation Mobile Computing, p. 444:

      An exception is Jabber, which is designed based on an open protocol called the extensible messaging and presence protocol (XMPP).

11. (medicine) The set of instructions allowing a licensed medical professional to start, modify, or stop a medical or patient care order. [from 20th c.]
12. (Roman Catholicism) The introduction of a liturgical preface, immediately following the Sursum corda dialogue.
13. (object-oriented programming) In some programming languages, a data type declaring a set of members that must be implemented by a class or other data type.

• (original notes of observations made during an experiment) procedure
• (official rules and guidelines for heads of state and other dignitaries) procedure, policy
• (accepted code of conduct) policy
• (data type defining a set of members) interface

• French: protocole
• Italian: protocollo
• Portuguese: protocolo
• Russian: протоко́л
• Spanish: protocolo

• French: protocole
• Russian: протоко́л

• Russian: протоко́л

• French: protocole
• German: Protokoll
• Italian: protocollo
• Portuguese: protocolo
• Russian: протоко́л
• Spanish: protocolo

protocol (protocols, present participle protocoling; simple past and past participle protocoled)

1. (obsolete, transitive) To make a protocol of.
2. (obsolete, intransitive) To make or write protocols, or first drafts; to issue protocols.
   • 1837, Thomas Carlyle, The French Revolution: A History […], volume (please specify |volume=I to III), London: Chapman and Hall, →OCLC ↗, (please specify the book or page number):

     Serene Highnesses, who sit there protocolling and manifestoing, and consoling mankind!

• German: protokollieren
• Russian: протоколи́ровать