Top giving me support (9)
I believe the answer is:
uppermost
'top' is the definition.
(similar in meaning)
'giving me support' is the wordplay.
'giving' indicates anagramming the letters (the letters give the letters for another word).
'me'+'support'='mesupport'
'mesupport' is an anagram of 'UPPERMOST'.
(Other definitions for uppermost that I've seen before include "Highest in place or rank" , "on top of the pile" , "At or nearest to the top" , "Highest or most prominent" , "get to top" .)