UMTEENTH is a playable word

umteenth Scrabble® Dictionary

adjective
being the last in an indefinitely numerous series
74 Playable Words can be made from "UMTEENTH"
   2-Letter Words (15 found)
   3-Letter Words (27 found)
   5-Letter Words (7 found)
   6-Letter Words (2 found)
   7-Letter Words (1 found)
   8-Letter Words (1 found)