One possibly sent out to get established (3,2)
I believe the answer is:
set in
'get established' is the definition.
I can't judge whether this definition defines the answer.
'one possibly sent out' is the wordplay.
'one' becomes 'i' (Roman numeral).
'possibly' is an anagram indicator.
'out' indicates putting letters inside.
'sent' anagrammed gives 'setn'.
'i' going inside 'setn' is 'SET-IN'.
'to' is the link.
Can you help me to learn more?
(Another definition for set in that I've seen is " Become established".)