Kryptonite is something that renders someone or something helpless and non-functioning. The word kryptonite was coined in 1943 in the comic book series, Superman, written by Jerry Siegel and inked by Joe Shuster. In the Superman canon, kryptonite is a mineral from Krypton, Superman’s home planet. Whenever in close proximity to kryptonite, Superman loses his superpowers. It is not clear how kryptonite works, but it is clear that radiation is somehow involved. The word kryptonite entered the popular culture quickly, and has become a term to describe a personal nemesis, a thing or person that saps the strength.
Examples
But the previous two meetings that mattered most, Wimbledon 2014 and Wimbledon 2015, went to Djokovic, Federer’s kryptonite. (The Los Angeles Times)
Rand Paul showing signs of being Hillary Clinton’s Kryptonite: poll (The Washington Times)
Maryland police did not easily find the kryptonite for this man with “superhuman strength.” (The New York Daily News)
But 2015 has indicated that just maybe Saratoga has once again donned its Superman cape, flexing its mighty muscles while developing an immunity to the kryptonite that is declining interest just about everywhere else. (The Troy Record)
Infidelity is to marriage what kryptonite is to Superman, poison is to rats, toasters are to bath time, nothing good comes from it. (The Holland Sentinel)
UBS saga may be kryptonite to Mike Baird’s super powers (The Sydney Morning Herald)
I thought I would never find this book in my lifetime, but I finally discovered my contemporary kryptonite, and am happy to state that you don’t always need dragons or magic to make a book awesome. (The Guardian)
There’s something sweet, something salty, something crispy, something crunchy, something bad for you that you can’t resist, either … your own personal kryptonite.
(The Toledo Blade)