Old English clænsian "to make clean; purge, purify, chasten; justify," from West Germanic *klainson, from *klainoz (see clean (adj.)). Despite its modern spelling (16c.), it retains its Middle English pronunciation. Related: Cleansed; cleansing.
Purgatory is supposed to cleanse you from your sins
cleaner
cleanliness
clean-living
cleanly
cleanness
cleanse
cleanser
cleansing
clean-up
clear
clearance