Why was "tantrum" trending last week?
1540s, as prothogall "draft of a document," from Middle French prothocole (c.1200, Modern French protocole), from Medieval Latin protocollum "draft," literally "the first sheet of a volume" (on which contents and errata were written), from Greek protokollon "first sheet glued onto a manuscript," from protos "first" (see proto-) + kolla "glue."
Sense developed in Medieval Latin and French from "official account" to "official record of a transaction," to "diplomatic document," and finally, in French, to "formula of diplomatic etiquette." Meaning "diplomatic rules of etiquette" in English first recorded 1896, from French; general sense of "conventional proper conduct" is from 1952. "Protocols of the (Learned) Elders of Zion," Russian anti-Semitic forgery purporting to reveal Jewish plan for world domination, first published in English 1920 under title "The Jewish Peril."
protocol pro·to·col (prō'tə-kôl', -kōl')
The plan for a course of medical treatment or for a scientific experiment.
Agreed-upon standards and practices in technology (particularly information technology) that allow systems manufactured by many different companies to be compatible with each other and work within common larger systems. Protocols are established by industry trade groups, governments, or some combination thereof.