radio drama vs audio drama

radio drama and audio drama both are nouns.

Word	Noun	Adjective	Verb	Adverb
radio drama	Yes	No	No	No
audio drama	Yes	No	No	No

As nouns, radio drama and audio drama are synonyms defined as:

radio drama and audio drama: a dramatized, purely acoustic performance, broadcast on radio or published on audio media, such as tape or CD.

Other synonyms of radio drama include radio theater, radio theatre.

radio drama (noun)	audio drama (noun)
a dramatized, purely acoustic performance, broadcast on radio or published on audio media, such as tape or CD.	a dramatized, purely acoustic performance, broadcast on radio or published on audio media, such as tape or CD.