Appropriate American support so raised (7)
I believe the answer is:
apropos
'appropriate' is the definition.
(associated in meaning)
'american support so raised' is the wordplay.
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'support' becomes 'prop' (prop up can mean to support).
'raised' says the letters should be written in reverse (going up in a down clue).
'so' backwards is 'os'.
'a'+'prop'+'os'='APROPOS'
(Other definitions for apropos that I've seen before include "To the point, germane" , "well-chosen" , "Suitable or relevant" , "Appropriate" , "fitting" .)