Jamboree used in English, as a borrowed foreign word, with the ending -ree. The word Jamboree is a transitive verb with a direct action of the primary word Jambo. For example, an attendee of a Jambo is a Jamboree. The word "Jamboree" is used primarily by the Scouting program before the first Boy Scout "Jamboree" in 1920. The word has also come to mean "a lavish or boisterous celebration or party" outside of the Scouting program. Baden-Powell deliberately chose the name "Jamboree" where attendees were warmly welcomed attending this first Boy Scout rally or meeting with the word "Jambo!" Many, at
1909 Crystal Palace Scout Rally and Boy Scouts from the British Boy Scouts, Church Scout Patrols and other Scouts not registered with what would become the Boy Scouts Association, leading to challenges regarding the 4th Scout Law that "A Scout is ... a brother to every other Scout". The Rally was a precursor to the later Scout Jamborees and World Scout Jamborees. The concept of the Scouts' Own, a simple, non-denominational religious ceremony, was also introduced by H. Geoffrey Elwes at this rally. Members of the local Scout Troop, 2nd Croydon (1st Crystal Palace Patrol), formed part of the flag party for Princess Christian, the