SERUM is a playable word

serum Scrabble® Dictionary

noun
pl. serums or sera
the watery portion of whole blood
(adjective) serumal
34 Playable Words can be made from "SERUM"
   2-Letter Words (8 found)
   3-Letter Words (13 found)
   4-Letter Words (10 found)
   5-Letter Words (3 found)