radiogram · noun1
From radio- (prefix denoting radioactivity or radiation) + -gram (suffix denoting something drawn, written, or otherwise recorded).
radiogram · noun2
Probably either: * from radio- (prefix denoting radio broadcasting) + -gram (suffix denoting something drawn, written, or otherwise recorded); or * a clipping of radio(tele)gram.
radiogram · noun3
Either: * a blend of radio + gram(ophone); or * a clipping of radiogram(ophone).
Etymology from Wiktionary, CC BY-SA 4.0.