Supporter distributed letters (7)
I believe the answer is:
trestle
'supporter' is the definition.
(I've seen this before)
'distributed letters' is the wordplay.
'distributed' indicates an anagram.
'letters' is an anagram of 'TRESTLE'.
(Other definitions for trestle that I've seen before include "Framework to support a flat surface -- letters (anag)" , "Braced framework" , "Simple table support" , "support of growth" , "Frame to hold table" .)