SERFS is a playable word

serf Scrabble® Dictionary

noun
pl. serfs
a member of the feudal class who lived and worked on another's land
18 Playable Words can be made from "SERFS"
   2-Letter Words (5 found)
   3-Letter Words (8 found)
   4-Letter Words (4 found)
   5-Letter Words (1 found)