Observes Yom Kippur
I believe the answer is:
atones
'observes yom kippur' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for atones that I've seen before include "Makes amends for sin" , "Makes up for, say sin" , "Makes up for injury or offence" , "Makes up for wrong done with a stone" , "Makes reparation" .)