D defs.my
Entry 1 sense Webster, 1913

umpteenth

· ump·teenth · IPA /ˈʌmp.tiːnθ/
01 a. Ordinal of umpteen, with corresponding signification; as, for the umpteenth time, I'm telling you to stop.
  1. 1.
    Ordinal of umpteen, with corresponding signification; as, for the umpteenth time, I'm telling you to stop.[Colloq.] See: umpteen