1600's, Wither, Weakness, Many giglets I have married seen Ere they forsooth could reach eleventeen.
(colloquial) A relatively large amount not precisely specified.
1919, Sinclair Lewis, Free Air, "He fitted about eleventeen thousand people last year."
2001, Rick D. Ellison, Gamble to Win: Craps, Trust me, I've checked every angle and analyzed a zillion options eleventeen different ways.
2004, Brooks Peterson, Cultural Intelligence: A Guide to Working with People from Other Cultures, I can make the locals laugh at my attempts in a few other languages, such as Swedish, but I'm certainly not like the average European who seems to speak "eleventeen" languages