Green’s Dictionary of Slang

(US) an uncountable large number.

1987		G. Tate in Flyboy in the Buttermilk (1992) 97: Never mind how many of those kerzillion LPs we bought.
1999		L. Gould Shagadelically Speaking 4: $1 kajillion bajillion, Figure the president of the United Sates mockingly suggests Dr. Evil might as well ask for when the latter demands a $100 billion payment.
2004		M.C. Nussbaum Animal Rights 293: She speaks to me, wide-eyed, of how there must be a ‘kabillion’ grains of sand.