Party ( Informal ) (7)
(Other definitions for shindig that I've seen before include "Big lively party (colloq.)" , "Noisy disturbance" , "Large and noisy party or quarrel" , "Hooley" , "Lively celebration (informal)" .)
(Other definitions for bash that I've seen before include "Party - whack" , "crash > party" , "Try - rave-up" , "Heavy blow; party" , "Party; beat" .)