Boisterous party (8)
(Other definitions for bash that I've seen before include "Smite; a party" , "Hit hard; party (slang)" , "box" , "Party; beat" , "Party (colloq.)" .)
(Other definitions for jamboree that I've seen before include "'Gala get-together, of scouts say (8)'" , "Large celebration" , "Lavish celebration" , "Lively celebration" , "Party - gathering of Scouts" .)