www.alphadictionary.com

The Indefinite Number; many

OED:
1905, "of an indefinite number," originally Morse code slang for "dash," influenced by association with numerals such as twenty, thirty, etc.; umpteen (1917) is World War I army slang, from umpty + teen

However, the disarmingly entertaining Uncyclopedia (qv) claimeth:

Umpteen is so called because it is ten plus ump. Ump was defined as umpteen minus ten by the Pythagoreans.

(ump tangentially being defined by the same source thus: Ump (or "umpt") is the base unit of the third axis of a three-dimentional number graph. Just as "math" (the base unit of the second axis on a two-dimentional number graph) is the square-root of math, ump is the square-root of umpteen)

At last my tired tagline gets the ball

Thank you!
So "ump" is the base unit of the third axis of a three dimensional number graph? Never knew that...just thought of it as someone to fuss at...

When counting, why don't we use the terms "onety-one, onety-two, onety-three,"(instead of eleven, twelve, etc.)--at least we'd be consistent! (If not funny sounding...)

So you wonder that too? Good. Better to be deranged in company.

It could be worse; we could count "four-twenties two" and "four-twenties seventeen" (97) as French does. They adapted it from the Celtic and failed to four-twenties six it.

Seems the most commonplace words are traditions that die hard. Let's not even get started on the days of the week...

PS note the spelling in the link: dementional

The Indefinite Number; many

OED:
1905, "of an indefinite number," originally Morse code slang for "dash," influenced by association with numerals such as twenty, thirty, etc.; umpteen (1917) is World War I army slang, from umpty + teen

However, the disarmingly entertaining Uncyclopedia (qv) claimeth:

Umpteen is so called because it is ten plus ump. Ump was defined as umpteen minus ten by the Pythagoreans.

(ump tangentially being defined by the same source thus: Ump (or "umpt") is the base unit of the third axis of a three-dimentional number graph. Just as "math" (the base unit of the second axis on a two-dimentional number graph) is the square-root of math, ump is the square-root of umpteen)

At last my tired tagline gets the ball

I never knew about the Uncyclopedia. What a riot!

As this has not yet been featured as a Good Word, I would like to renew this suggestion (see the discussion above).

And here I was thinking it referred to an adolescent who called balls and strikes behind home plate.

I was thinking that Humpty Dumpy broke into umpteen pieces.