Signed off pattern (6)
I believe the answer is:
design
'pattern' is the definition.
(I know that pattern can be written as design)
'signed off' is the wordplay.
'off' indicates an anagram.
'signed' with letters rearranged gives 'DESIGN'.
(Other definitions for design that I've seen before include "Pattern - plan" , "End" , "Plan for specific purpose" , "Plan, drawing" , "Devise, dreate, make out a plan" .)