Offer support, also reforms (8)
I believe the answer is:
proposal
'offer' is the definition.
(proposal is a kind of offer)
'support also reforms' is the wordplay.
'support' becomes 'prop' (prop is a kind of support).
'reforms' is an anagram indicator.
'also' is an anagram of 'osal'.
'prop'+'osal'='PROPOSAL'
(Other definitions for proposal that I've seen before include "motion" , "union offer?" , "A suggestion, perhaps of marriage" , "Offer - suggestion" , "Offer (to get spliced?)" .)