quintillion /kwɪnˈtɪljən/number 4noun 1forms 1 number4 •Either of two very large amounts. •A billion billion: 1 followed by eighteen zeros, 10¹⁸; one million million million.Last week, we used[…]the BBC News website's biggest number: 9,223,372,036,854,775,808, that's 9.2 quintillion[…][the maximum video viewer count on YouTube's] updated counter software. — 2014 •(UK, old-fashioned) A million quadrillion: 1 followed by 30 zeros, 10³⁰. •(informal) An unspecified very large number.He had like a quintillion excuses for why he couldn't meet his obligation to me. noun1 •(slang, figurative) Any very large number, exceeding normal description. formsquintillions
