Greedily wanting one new standard assessment task, one in competent style (10)
I believe the answer is:
insatiably
'greedily' is the definition.
Both the definition and answer are adverbs. Perhaps there's an association between them I don't understand?
'one new standard assessment task one in competent style' is the wordplay.
'one' becomes 'i' (Roman numeral).
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'standard assessment task' becomes 'SAT' (former name for UK SAT exam).
'one' becomes 'i' (Roman numeral).
'in competent style' becomes 'ably' (I am not sure about this - if you are sure you should believe this answer much more).
'i'+'n'+'sat'+'i'+'ably'='INSATIABLY'
'wanting' is the link.
Can you help me to learn more?