kryptonite

[krip-tuh-nahyt]

noun

1. Usually Kryptonite a fictional radioactive substance that is the only thing capable of hurting or weakening the otherwise invulnerable superhero Superman.

   Exposure to Kryptonite nullifies Superman's powers and immobilizes him with pain.

2. Sometimes Kryptonite something that a person or thing cannot defend against or defeat; a nemesis or bête noire.

   The team has not found a way to stop the triple option attack, which has been their kryptonite over the last several years.

   Garlic oil is kryptonite for aphids.

Word History and Origins

Origin of kryptonite¹

Coined in 1943 by writer and producer George Lowther (1913–1975); krypton ( def. ) + -ite ¹ ( def. )

Example Sentences

“It’s been like Kryptonite for years for many filmmakers and producers to get it right.”

From Los Angeles Times

A few minutes later, though, we stumble upon her kryptonite.

From Los Angeles Times

His kryptonite at the venue is spin – against pace bowling Smith averages 112.75 at the home of cricket, but that figure plummets to 23.33 against the tweakers.

From BBC

But Alcaraz has proved to be Sinner's kryptonite of late.

From BBC

“I read a book that had, like, 37 psychiatrists talking about Trump’s malignant narcissism and they said people like that, their kryptonite is being laughed at,” says Hamill, a lifelong comic-book fan who often speaks in superhero metaphors.

From Los Angeles Times