Definitions

1. adjective

used to describe the ninth or a very large but indefinite number in a series.

“The umpteenth time I had to deal with their customer service, I was about to lose my patience.”

2. adverb

to a very large or indefinite number, especially the ninth time.

“She has broken her leg umpteenth times due to her love for extreme sports.”

3. noun

a very large but indefinite number, especially the ninth in a series.

“The umpteenth meeting with the team failed to yield a solution to the problem.”