Coppers taking steps for epidemic (10)
I believe the answer is:
pestilence
'epidemic' is the definition.
(I've seen this before)
'coppers taking steps' is the wordplay.
'coppers' becomes 'pence' (I've seen this before).
'taking' indicates putting letters inside.
'steps' becomes 'stile' (I've seen this in other clues).
'pence' going around 'stile' is 'PESTILENCE'.
'for' acts as a link.
(Other definitions for pestilence that I've seen before include "Deadly epidemic disease" , "evil force" , "that'll plague you" , "it's an agent of evil" , "Epidemic disease with a high death rate" .)