[1940–45; radio- + autograph]This word is first recorded in the period 1940–45. Other words that entered Englishat around the same time include: Rh factor, black box, blockbuster, set-aside, silkscreenradio- is a combining form with the meanings “dealing with radiant energy” (radiometer), “employing or dealing with radio waves” (radioacoustics; radiolocation; radiotelephone), “emitting rays as a result of the breakup of atomic nuclei” (radioactive; radiocarbon), “characterized by, employing or dealing with such rays” (radiography; radiopaque; radiotherapy)