REGULI is a playable word

regulus Scrabble® Dictionary

noun
pl. reguluses or reguli
a mass that forms beneath the slag in a furnace
(adjective) reguline
42 Playable Words can be made from "REGULI"
   2-Letter Words (5 found)
   3-Letter Words (15 found)
   4-Letter Words (13 found)
   5-Letter Words (5 found)
   6-Letter Words (4 found)