What does the ray in X-ray mean?

Answer 1

Wilhelm Röntgen was the one who gave them the name "X-rays", though many referred to these as "Röntgen rays" for several decades after their discovery. The presence of some unknown ray was deduced from its effect on photographic film/plates when sealed in light tight containers. Röntgen referred to the radiation as "X", to indicate that it was an unknown type of radiation. The name stuck, although (over Röntgen's great objections) many of his colleagues suggested calling them Röntgen rays. They are still referred to as such in many languages, including German.

Answer 2

Ray.the x ray is a ray of light, of radiation. radiation which does not pass through your bones and there fore can be used to examine bones that are broken or sprained

Answer 3

Nothing, back when they where invented because they didn't knew what it was they put the x on the name.