Quote position on the radio? (4)
I believe the answer is:
cite
'quote' is the definition.
(I know that quote can be written as cite)
'position on the radio?' is the wordplay.
'position' becomes 'site' (site is a kind of position).
'on the radio?' indicates a 'sounds like' (homophone) clue (I've seen 'on the radio' mean this).
'site' sounds like 'CITE'.
(Other definitions for cite that I've seen before include "Give as an example" , "Quote (a reference)" , "Quote (an author)" , "Summons - quote" , "Use quotations" .)