25 June 2015
The latest additions to the OED Online includes an entry for kryptonite. Definition:
In the fictional world of the comic book hero Superman: a substance that renders Superman weak and powerless. Hence in figurative or allusive use: something that can weaken or damage a particular person or thing; an Achilles heel.
And the dictionary includes the following note:
Kryptonite is most commonly depicted as a green mineral that came to earth from Krypton, Superman’s home planet, following its destruction. Other types have appeared in various comic books, films, etc., each having different properties.
Kryptonite first appears on the Superman radio program in 1943. It’s comic book appearance dates from 1949. The earliest figurative use cited by the OED is from 1965.
