Offer support to little old Sarah (8)
I believe the answer is:
proposal
'offer' is the definition.
(proposal is a kind of offer)
'support to little old sarah' is the wordplay.
'support' becomes 'prop' (prop is a kind of support**).
'to little' says to take the initial letters.
'sarah' becomes 'sal' (Sally is a common pet form of Sarah).
The initial letter of 'old' is 'o'.
'prop'+'o'+'sal'='PROPOSAL'
(Other definitions for proposal that I've seen before include "Suggestion put forward for consideration" , "A suggestion, perhaps of marriage" , "Plan, suggestion" , "motion" , "Kind of offer, perhaps of marriage" .)