Coppers may get old, yet still be progressive (4)
I believe the answer is:
plod
'coppers may get old yet still be progressive' is the definition.
I can't judge whether this defines the answer.
'coppers may get old' is the wordplay.
I cannot quite understand how this works, but
'coppers' could be 'p' and 'p' is found in the answer.
an anagram of 'old' is 'lod' which is located in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for plod that I've seen before include "Slow heavy walk" , "Walk slowly and laboriously" , "Walk with effort" , "Policeman - walk slowly" , "Walk slowly and heavily" .)