What does Boxing Day have to do with boxing?
late 14c., from Old French restoratif from restorer (see restore).
early 15c., from restorative (adj.), or from Medieval Latin restaurativum "a restorative."
restorative re·stor·a·tive (rĭ-stôr'ə-tĭv)adj.
Of or relating to restoration.
Tending or having the power to restore.