Promise support for advisory body (9)
I believe the answer is:
committee
'advisory body' is the definition.
'committee' can be an answer for 'body' (thesaurus). I am unsure of the 'advisory' bit.
'promise support' is the wordplay.
'promise' becomes 'commit' (I've seen this before).
'support' becomes 'tee' (tee is a kind of support).
'commit'+'tee'='COMMITTEE'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for committee that I've seen before include "Group delegated to consider matters" , "Board" , "Group selected to undertake certain duties" , "Panel set up for a purpose" , "politburo, perhaps" .)