Examples of “insanity” in a Sentence

noun Serious mental illness; the state of being of unsound mind.

• His lawyer argued a defense of insanity.
• She wrote a novel about a character slowly sinking into insanity.
• Years of isolation drove the old lighthouse keeper to the edge of insanity.

noun Extreme foolishness or a chaotic, reckless situation.

• Trying to finish the project in one night is pure insanity.
• Cycling across the city at rush hour without lights is sheer insanity.
• The shop was pure insanity on the last Saturday before the holidays.