[1] : The Collaborative International Dictionary of English v.0.48

umpteen \ump"teen\, a.
   an indefinite number, usu. more than ten and less than one
   hundred; a lot. often used hyperbolically, and usually
   expressing the notion of more than the usual number or more
   than i would like. colloq. "i've told you umpteen times not
   to do that."
   pjc

[2] : WordNet (r) 2.0

umpteen
     adj : innumerable but many syn: umteen
see also:
umteen 

Umpteen >> U Words
Umpteen, definition of term: Umpteen
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