Copy perplexed clients (7)
I believe the answer is:
stencil
'copy' is the definition.
(thesaurus)
'perplexed clients' is the wordplay.
'perplexed' indicates an anagram.
'clients' anagrammed gives 'STENCIL'.
(Other definitions for stencil that I've seen before include "Cut out pattern for painting a design" , "Cut-out master pattern" , "Aid for drawing" , "office plate" , "Template for pattern" .)