EXTREMUM is a playable word

extremum Scrabble® Dictionary

noun
pl. extrema
a maximum or a minimum of a mathematical function
56 Playable Words can be made from "EXTREMUM"
   2-Letter Words (12 found)
   3-Letter Words (20 found)
   4-Letter Words (13 found)
   5-Letter Words (10 found)
   8-Letter Words (1 found)