What does kryptonite mean?
Kryptonite is best known as a fictional radioactive mineral from the planet Krypton, where its presence can deprive a superhero of extraordinary powers. The substance became culturally recognizable through superhero stories from the early 1940s and has since acquired a broader figurative meaning. In that use, kryptonite denotes a weakness that is especially damaging because it strikes at a vulnerable or indispensable point. A company might call a competitor's monopoly its kryptonite, while a strategist might describe a disruptive technology as kryptonite to an established institution. The expression combines the scientific connotations of radioactivity with a simple narrative pattern: the apparently powerful figure is rendered helpless by a material associated with its home world. Because it is widely understood, kryptonite is effective in popular culture, journalism, and informal commentary, though it can sound playful or exaggerated in serious discussion.
nounA fictional radioactive mineral from the planet Krypton whose exposure causes a superhero to lose their powers. By extension, the term can refer metaphorically to something that severely weakens or disables a person, organization, or plan.
- A fictional radioactive mineral or substance associated with the planet Krypton, exposure to which deprives a superhero of their powers.
- A thing or circumstance that seriously weakens or disables someone or something.
"The team discovered that the disruption was the financial equivalent of kryptonite."
"The scientist believed the mineral was ordinary rock until she realized it was kryptonite."
"Centralized control can become the corporation's kryptonite."
The plural is occasionally used when referring to multiple pieces, doses, or types of the fictional substance.
"The spacecraft was protected against several forms of kryptonite."
What if a superhero's greatest threat were a rock? Kryptonite turned a fictional planet's mineral into an enduring symbol of vulnerability.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does kryptonite come from?
The word was coined for superhero fiction in the early 1940s by combining krypton, the name of the fictional planet, with the mineral-forming suffix -ite. Krypton itself was coined from Greek kryptos, meaning “hidden” or “concealed.” The resulting name carries a comic-book origin but has developed into a general metaphor for a powerful and threatening weakness.
How kryptonite is actually used
The word originated as a specific fictional substance but is now used figuratively, especially for a powerful person's or organization's crucial weakness. Capitalization varies: it is often capitalized when referring to the fictional mineral and lowercase in extended metaphorical use.
Easily confused with kryptonite
Krypton is a real chemical element, whereas kryptonite is a fictional radioactive mineral created for superhero stories.