Electromagnetic wave and Radio wave

Electromagnetic wave noun - Radiation consisting of waves of energy associated with electric and magnetic fields resulting from the acceleration of an electric charge.

Radio wave and electromagnetic wave are semantically related. In some cases you can replace phrase "Radio wave" with "Electromagnetic wave", this phrases are similar.

Radio wave noun - An electromagnetic wave with a wavelength between 0.5 cm to 30,000 m.

Electromagnetic wave and radio wave are semantically related. You can use "Electromagnetic wave" instead a noun phrase "Radio wave".