■ noun
1》 the official procedure or system of rules governing affairs of state or diplomatic occasions.
↘the accepted code of procedure or behaviour in a particular situation.
2》 the original draft of a diplomatic document, especially of the terms of a treaty agreed to in conference and signed by the parties.
↘an amendment to a treaty or convention.
3》 a formal record of scientific experimental observations.
↘a procedure for carrying out a scientific experiment or a course of medical treatment.
4》 Computing a set of rules governing the exchange or transmission of data between devices.
Origin
ME (denoting the original note of an agreement): from OFr. prothocole , via med. L. from Gk prōtokollon 'first page, flyleaf'.