Rontgenn. 伦琴(X射

)
rontgen[ noun ]German physicist who discovered x-rays and developed roentgenography (1845-1923)<noun.person> 
Rontgen \R["o]nt"gen\, Roentgen \Roent"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.
[Webster 1913 Suppl.]