Pet term concocted for Devil (7)
I believe the answer is:
tempter
'devil' is the definition.
(I know that devil can be written as Tempter)
'pet term concocted' is the wordplay.
'concocted' is an anagram indicator.
'pet'+'term'='petterm'
'petterm' is an anagram of 'TEMPTER'.
'for' acts as a link.
(Other definitions for tempter that I've seen before include "The Devil?" , "One offering enticements" , "Satan" , "One offering enticement" , "Siren" .)