late Middle English (denoting the original minute of an agreement, forming the legal authority for future dealings relating to it): from Old French prothocole, via medieval Latin from Greek prōtokollon ‘first page, flyleaf’, from prōtos ‘first’ + kolla ‘glue’. Sense 1 derives from French protocole, the collection of set forms of etiquette to be observed by the French head of state, and the name of the government department responsible for this (in the 19th century).