Pinch offender and put in special enclosure (6)
I believe the answer is:
scrimp
'pinch' is the definition.
(thesaurus)
'offender and put in special enclosure' is the wordplay.
I cannot quite see how this works, but
'offender' could be 'crimp' (crimp is a kind of offender) and 'crimp' is found in the answer.
'special' could be 's' (common abbreviation as in Special Air Service) and 's' is found within the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for scrimp that I've seen before include "Be niggardly" , "Do or spend less than is needed" , "Be prudent" , "Economise, be thrifty" , "To pinch pennies" .)