LUMEN is a playable word

lumen Scrabble® Dictionary

noun
pl. lumens or lumina
the inner passage of a tubular organ
(adjective) lumenal, luminal
22 Playable Words can be made from "LUMEN"
   2-Letter Words (9 found)
   3-Letter Words (8 found)
   4-Letter Words (4 found)
   5-Letter Words (1 found)