a violation of what is sacred, e.g. the improper or secular use of a sacred object
gross irreverence towards somebody or something sacred
sacrilegious /-ʹlijəs/ adj
sacrilegiously /-ʹlijəsli/ adv
[Middle English via Old French from Latin sacrilegium, from sacrilegus one who steals sacred things, from sacr-, sacer sacred + legere to gather, steal]