A word that usually prescribes an uncertain number of occurances. This is usually said in the reference of the numbers 13-19 (hence the 'teen'), but it can be in reference to any number within reason.

Hence 'umteenth'
I got umpteen calls from this pranker yesterday.

I dyed my hair for the umpteenth time today.
by Cheezu$ July 26, 2003
An expression which denotes an abundance, large quantity, huge amount or a load of something. The word "umpteenth" was derived from "umpteen" and means "for-God-knows-which-time".
There was an umpteen of fidgety tourists in the city endeavouring to do as much sightseeing as it was possible.
by necrotism June 4, 2007
The goldfish fidgets umpteen times.
by -AG June 24, 2013
The greatest number...What.. Were you expecting more from the definition?That's all I need to say.
Person 1:What's your favourite number?
Person 2:My favourite number is umpteen.
Person 1:Mine too.
by Umpteen4life May 8, 2018
The most awesome number ever. What? .. Were you expecting more?
John: Hey Chad .
Chad: What?
John: What's your favourite number?
Chad: Umpteen
John: Mine too
by Umpteen4life May 26, 2018