Umpteen/ˌʌmpˈtiːn/ Definition 1 of 1Pro Tip 1/3Slight Exaggeration Used to indicate a higher number than actual to emphasize there's a lot without being specific. I've explained this to you umpteen times! Pro Tip 2/3Informal Usage Commonly used in casual conversation rather than formal writing or speeches. She's brought umpteen snacks for the road trip. Pro Tip 3/3Uncountable Items Refers to things you can't or haven't counted exactly, often for effect. There are umpteen stars in the sky tonight.