Soon, there followed umpteen, blending umpty and -teen. Umpteen usually describes an indefinite and large number or amount, while the related umpteenth is used for the latest or last in an indefinitely numerous series.

Is umpteenth a real number?

Umpteenth comes from umpty, meaning an indefinite number. Etymology Online says "umpty" is derived from "Morse code slang for "dash," influenced by association with numerals such as twenty, thirty, etc."

What is an umpteenth?

: latest or last in an indefinitely numerous series Wiping mashed banana out of your toddler's hair for the umpteenth time can be—let's face it—tedious and irritating.—