cardinal sin

British  

noun

1. theol any of the seven deadly sins

2. informal an unforgivable error or misjudgment

   lack of impartiality is considered a cardinal sin in broadcasting circles

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Example Sentences

Perhaps the cardinal sin in Garten’s Thanksgiving guidebook is waiting until the very last minute to prepare and serve your Thanksgiving meal.

From Salon

NBA commissioner Adam Silver has called cap circumvention “a cardinal sin.”

From The Wall Street Journal

And viewpoint-based discrimination is a cardinal sin under the First Amendment.

From Slate

NBA Commissioner Adam Silver has called attempts to circumvent it a “cardinal sin.”

From Los Angeles Times

They add up to an erasure of self, its meaning elusive: “This was a cardinal sin; you could not become interested in the illness. You could not lavish on it the love and solicitation you had previously lavished on the self, even though it was the thing the self was replaced by.”

From Los Angeles Times