Jug for coppers? No sir! (6)
I believe the answer is:
prison
'jug' is the definition.
(thesaurus)
'coppers? no sir' is the wordplay.
I cannot really see how this works, but
'coppers?' could be 'p' and 'p' is located in the answer.
'no' could be 'o' (resembles 0 - 'no' can mean 'zero') and 'o' is found within the answer.
an anagram of 'sir' is 'ris' which is present in the answer.
A single letter 'n' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
'for' is the link.
Can you help me to learn more?
(Other definitions for prison that I've seen before include "Penitentiary" , "Cooler" , "Gaol" , "cage" , "punishment" .)