Target of coastal erosion? Absolutely true, as heard on the radio (8)
I believe the answer is:
littoral
'target of coastal erosion? absolutely true' is the definition.
I can't tell whether this defines the answer.
'as heard on the radio' is the wordplay.
'as' becomes 'litt' (I can't justify this - if you can you should give a lot more credence to this answer).
'heard' becomes 'aural' (aural means relating to hearing).
'on the radio' shows a homophone (sound like).
'aural' is a homophone of 'oral'.
'litt'+'oral'='LITTORAL'
Can you help me to learn more?
(Other definitions for littoral that I've seen before include "seashore" , "Of or on the sea shore" , "seaside locale" , "Coastal strip" , "sandy area?" .)