Fan letters providing support (7)
I believe the answer is:
trestle
'support' is the definition.
(I've seen this before)
'fan letters' is the wordplay.
'fan' is an anagram indicator (letters must be fanned around).
'letters' anagrammed gives 'TRESTLE'.
'providing' acts as a link.
(Other definitions for trestle that I've seen before include "Supporting framework for, eg, table top" , "Framework to hold table top" , "Framework for holding a tabletop" , "Braced framework" , "Braced support" .)