Contracted a gluttonous vice (6)
I believe the answer is:
agreed
'contracted a gluttonous vice' is the definition.
'agreed' can be an answer for 'contracted' (thesaurus). I am not sure about the 'a gluttonous vice' bit.
'contracted a gluttonous' is the wordplay.
'contracted' means to remove the last letter (to contract is to shorten).
'gluttonous' becomes 'greedy' (similar in meaning).
'a'+'greedy'='agreedy'
'agreedy' with its last letter removed is 'AGREED'.
Can you help me to learn more?
(Other definitions for agreed that I've seen before include "It's a deal!" , "Done!" , "matched" , "Accorded" , "Let's do it!" .)