Use 'sacrilege' to express a severe lack of respect towards what is sacred to a culture or religion. Spray painting graffiti on the church wall was seen as sacrilege.
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Figurative Use
'Sacrilege' can be used figuratively to refer to disrespecting something highly valued, not only religious. In our family, not following Grandma's pie recipe is considered sacrilege.
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Strong Emotions
The word 'sacrilege' often carries a strong emotional weight and indicates deep offense. Fans cried out sacrilege when the ancient stadium was demolished.