Meaning of “radio” - Learner’s Dictionary

radio

noun uk us /ˈreɪdiəʊ/
BROADCASTS [ C ]

A1 a piece of equipment used for listening to radio broadcasts:

a car radio
the radio

A1 the programmes that you hear when you listen to the radio:

We heard him speaking on the radio this morning.
I listen to the radio in the evening.
SYSTEM [ U ]

B1 a system of sending and receiving sound through the air:

local radio
a radio station
MESSAGES [ C ]

(Definition of “radio noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)