Desperate Merton needs support (11)
I believe the answer is:
endorsement
'support' is the definition.
(I know that endorsement is a type of support)
'desperate merton needs' is the wordplay.
'desperate' is an anagram indicator (a desperate or pathetic spelling).
'merton'+'needs'='mertonneeds'
'mertonneeds' is an anagram of 'ENDORSEMENT'.
(Other definitions for endorsement that I've seen before include "Sanction, backing" , "Penalty appended to driving licence" , "Support and approval" , "Note on a driving licence" , "Green light" .)