Source : Webster's Revised Unabridged Dictionary (1913)

Rontgen \R["o]nt"gen\, a.
   Of or pertaining to the German physicist Wilhelm Konrad
   R["o]ntgen, or the rays discovered by him; as, R["o]ntgen
   apparatus.

Source : WordNet®

Rontgen
     n : German physicist who discovered x-rays and developed
         roentgenography (1845-1923) [syn: {Roentgen}, {Wilhelm
         Konrad Roentgen}, {Wilhelm Konrad Rontgen}]