protocol

UK: /ˈprəʊtəʊkɒl/

US: /ˈproʊtəˌkɔl, -ˌkɑl/

US: (prō′tə kôl′, -kol′, -kōl′)

WordReference Random House Learner's Dictionary of American English © 2026

pro•to•col /ˈproʊtəˌkɔl, -ˌkɑl/   n. 

1. Government [uncountable] the customs, rules, and regulations dealing with formal courtesies, good manners, or diplomatic relations between countries.
2. Government [countable] an original draft, or part of a written record from which a document, esp. a treaty, is prepared.
3. Computing [countable] a set of rules governing the format of messages exchanged between computers.

WordReference Random House Unabridged Dictionary of American English © 2026

pro•to•col  (prō′tə kôl′, -kol′, -kōl′), n. 

1. Government the customs and regulations dealing with diplomatic formality, precedence, and etiquette.
2. Government an original draft, minute, or record from which a document, esp. a treaty, is prepared.
3. Government a supplementary international agreement.
4. Government an agreement between states.
5. Government an annex to a treaty giving data relating to it.
6. Medicine the plan for carrying out a scientific study or a patient's treatment regimen.
7. Computing a set of rules governing the format of messages that are exchanged between computers.
8. Philosophy Also called pro′tocol state′ment, pro′tocol sen′tence, pro′tocol proposi′tion. a statement reporting an observation or experience in the most fundamental terms without interpretation: sometimes taken as the basis of empirical verification, as of scientific laws.

v.i. 

9. Government to draft or issue a protocol.

• Late Greek prōtókollon origin, originally, a leaf or tag attached to a rolled papyrus manuscript and containing notes as to contents. See proto-, colloid
• Medieval Latin prōtocollum
• 1535–45; earlier protocoll

pro•to•col•ar  (prō′tə kol′ər), pro′to•col′a•ry, pro′to•col′ic, adj. 

Collins Concise English Dictionary © HarperCollins Publishers::

protocol / ˈprəʊtəˌkɒl/ noun

1. the formal etiquette and code of behaviour, precedence, and procedure for state and diplomatic ceremonies
2. a memorandum or record of an agreement, esp one reached in international negotiations, a meeting, etc
3. (chiefly US) a record of data or observations on a particular experiment or proceeding
4. an annexe appended to a treaty to deal with subsidiary matters or to render the treaty more lucid
5. an amendment to a treaty or convention
6. a statement that is immediately verifiable by experience
   See logical positivism
7. the set form in which data must be presented for handling by a particular computer configuration, esp in the transmission of information between different computer systems

Etymology: 16th Century: from Medieval Latin prōtocollum, from Late Greek prōtokollon sheet glued to the front of a manuscript, from proto- + kolla glue