emphasis You use umpteenth to indicate that an occasion, thing, or person happens or comes after many others. He checked his watch for the umpteenth time She was now on her umpteenth gin. if something happens for the umpteenth time, it happens again after having happened many times before - used when you are annoyed that it has happened so often (umpty (a joke word) (1900-2000) + -teenth (as in thirteenth))
emphasis Umpteen can be used to refer to an extremely large number of things or people. He was interrupted by applause umpteen times He has produced umpteen books, plays and television series. = countless. very many - used especially when you are annoyed there are so many