kryptonite
noun
kryp·to·nite
ˈkrip-tə-ˌnīt 
variants
or Kryptonite
in stories
: a substance that causes the comic-book character Superman to become weak when he is exposed to it
Note: In Superman stories, kryptonite in its most familiar form is a green mineral that originated as part of Superman's home planet of Krypton and that falls to Earth as a meteorite.
Superman tended to get more bummed out by Kryptonite than by anything going on in Clark Kent's life …—
Tom Russo
—often used to describe something likened to kryptonite in causing someone's weakness, failure, etc.Tom RussoIn his career Thome has hit less than .240 against lefties. Lefthanded power pitching is Thome's Kryptonite …—Joe Posnanski
Joe PosnanskiIronic people always dissolve when confronted with earnestness, it's their kryptonite.—Gillian Flynn
Gillian Flynn"Thin people know they need to either limit exposure to certain foods that trigger appetite or limit the quantity or frequency of those foods," says Gullo, whose personal kryptonite is pizza.—Lorie Parch
Lorie ParchEffortlessly good-looking, he was also a talented writer—that combo was my kryptonite.—Taylor Orci
Taylor OrciExamples of kryptonite in a Sentence
Recent Examples on the Web
Luckily, Clarissa figured out her kryptonite: a crush on Clarissa's dorky little brother, Ferguson.
—Angela Andaloro, People.com, 26 Feb. 2025
Reason to be fearful: The Etihad is Liverpool’s kryptonite, having not won there in the league since Jurgen Klopp’s first season in charge in 2015.
—Andy Jones, The Athletic, 18 Feb. 2025
The Bills are attempting to take down the Chiefs, who have been the team's proverbial kryptonite for years.
—Joel Thayer, Newsweek, 27 Jan. 2025
Jost’s kryptonite was still his mouth on his face telling jokes at the expense of Black people.
—Tony Maglio, IndieWire, 10 Feb. 2025
See All Example Sentences for kryptonite
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Angela Andaloro, People.com, 26 Feb. 2025
Reason to be fearful: The Etihad is Liverpool’s kryptonite, having not won there in the league since Jurgen Klopp’s first season in charge in 2015.
—Andy Jones, The Athletic, 18 Feb. 2025
The Bills are attempting to take down the Chiefs, who have been the team's proverbial kryptonite for years.
—Joel Thayer, Newsweek, 27 Jan. 2025
Jost’s kryptonite was still his mouth on his face telling jokes at the expense of Black people.
—Tony Maglio, IndieWire, 10 Feb. 2025
See All Example Sentences for kryptonite
Articles Related to kryptonite
Cite this Entry
“Kryptonite.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/kryptonite. Accessed 4 Mar. 2025.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
Share