often a royal address to the inner court ends with the salutation put forward by attendees of 'hip hip hooray', at the conclusion, its like a declaration of support for whatever messages or directives were announced.

From this we got the term 'being hip' to something, which often implies being 'in on' something. A secret. Or in the case of an intel briefing or meeting.
And from that emerged 'the hippies'. The people who were 'hip' to the secret agenda. In other words, the 'hippies' were the intel people tasked with carrying out the secret plans.

ETYMOLOGY OF "HURRAH."

Mr. Spratley Says That We Get It From Ancient Egypt. W. J. Spratley, to use his plain English name, has favored us with a copy of a letter addressed to The Institute and Lecturers' Gazette on the etymology of the word "Hurrah!" which Mr. Spratley spells "Hoorah!" We have been vaguely cherishing the idea that it had a Russian origin, but Mr. Spratley ties us to ancient Egypt in his etymological search He thinks •' there can be no doubt that the Egyptian soldiers went into battle to the inspiriting cheer of' Hooßa! Hooßa! Hooßa!'"

Hooßa (in the tongue of the Thothmes and Rameses) means 'The king, the king, the king!' Yea, more. As 'Ra' means not only king, but also God and man, the concentrated meaning <>i the cry would be, 'For God, king and country!' What more loyal, what mor.i patriotic, what more devout?" What, indeed 1

But lest we should haply still doubt, Mr. Spratley clinches the matter by citing, in corroboration, the fact that his name, in Egyptian roots, is Sa-pa-Ra-ta-y, or Sa-pa-Hoo-Ra-ta-y, which means "Son of heaven, king -of the two hemispheres, https://cdnc.ucr.edu/cgi-bin/cdnc?a=d&d=MJ18980804.2.5&e=-------en--20--1--txt-txIN--------1

And then of course we have 'hip hop', which arrived about the same time as the hippies.

Hypnosis?