This is the full read-only archive of the "Ask the Wordwizard" section of the original Wordwizard site. The responses to the questions originate from Jonathon Green, the compiler of the Cassell Dictionary of Slang and numerous other dictionaries.
where did "X-ray" get its name from?
what does the "X" stand for?
Submitted by Brett Anderson (Marlborough - U.S.A.)
Signature: Topic imported and archived
X-ray is the English translation of German 'x-strahlen', the name given by Röntgen to the rays in question, expressing the fact that their essential nature was unknown. 'X' has been used in algebra to denote an unknown or variable quantity since c.1660; its use as ‘an unknown number of ...’ emnrged in 1848.
Signature: Jonathon Green