Retro song from soldier (5)
I believe the answer is:
oldie
'retro song' is the definition.
'oldie' can be an answer for 'song' (I have seen 'Song of yesteryear ' mean 'oldie' so perhaps 'song' could also mean 'oldie'). I'm not certain of the 'retro' bit.
'from soldier' is the wordplay.
'from' indicates the answer is hidden within the clue.
'OLDIE' can be found hidden inside 'soldier'.
Can you help me to learn more?
(Other definitions for oldie that I've seen before include "Standard song" , "Perennially popular song or film, often golden" , "pensioner" , "One getting on" , "Former song or film that is still well-known" .)