Very large indefinite number (informal) (7)

I believe the answer is:

zillion

(Other definitions for zillion that I've seen before include "Mind-blowing number" , "Unspecified enormous number" , "Indefinite large number, lots of noughts" , "Many millions" , "Great quantity" .)

I've seen this clue in The Guardian.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.