ISTHMI is a playable word

isthmus Scrabble® Dictionary

noun
pl. isthmuses or isthmi
a strip of land connecting two larger land masses
30 Playable Words can be made from "ISTHMI"
   2-Letter Words (8 found)
   3-Letter Words (9 found)
   4-Letter Words (9 found)
   5-Letter Words (2 found)
   6-Letter Words (2 found)