Definition of radio radar in US English:

radio radar

noun

  • Radar that uses radio waves (rare).

adjective

  • (attributive, with hyphen) involving or relating to radio and radar; specifically designating a radio telescope that, in addition to detecting radio waves received from space, can also operate using radio waves that it transmits for subsequent reflection by an asteroid, planet, etc.

Origin

1940s; earliest use found in The Sheboygan Press.