Offered support in getting established (6)
I believe the answer is:
rooted
'established' is the definition.
(similar in meaning)
'offered support in' is the wordplay.
I cannot really understand how this works, but
'support' could be 'root' (I've seen this before) and 'root' is present in the answer.
The remaining letters 'ed' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'getting' acts as a link.
Can you help me to learn more?
(Other definitions for rooted that I've seen before include "Stuck in one place, like plant" , "Firmly established and well planted" , "Deeply felt" , "Firmly attached as plants are to ground" , "Fixed to the spot like a plant" .)